View source for Surface-supplied diving

{{Short description|Underwater diving breathing gas supplied from the surface}}

[[File:AquariumDiver.jpg|thumb|right|Surface-supplied diver at the [[Monterey Bay Aquarium]], Monterey, California]]
[[File:US Navy 051026-N-0000X-001 Electronics Technician 1st Class Matthew Ammons, a diver assigned to Mobile Diving and Salvage Unit Two (MDSU-2), is fitted with a Kirby Morgan 37 Dive Helmet.jpg|thumb|right|US Navy Diver using Kirby Morgan Superlight 37 diving helmet<ref name=ADA166891 />]]

'''Surface-supplied diving''' is a [[mode of underwater diving]] using equipment supplied with [[breathing gas]] through a [[Umbilical cable#Diver|diver's umbilical]] from the surface, either from the shore or from a [[diving support vessel]], sometimes indirectly via a [[diving bell]].<ref name=gernhardt /> This is different from [[scuba diving]], where the diver's breathing equipment is completely self-contained and there is no essential link to the surface. The primary advantages of conventional surface supplied diving are lower risk of drowning and considerably larger breathing gas supply than scuba, allowing longer working periods and safer decompression. It is also nearly impossible for the diver to get lost. Disadvantages are the absolute limitation on diver mobility imposed by the length of the umbilical, encumbrance by the umbilical, and high logistical and equipment costs compared with scuba. The disadvantages restrict use of this mode of diving to applications where the diver operates within a small area, which is common in commercial diving work.

The copper helmeted free-flow [[standard diving dress]] is the version which made [[commercial diving]] a viable occupation, and although still used in some regions, this heavy equipment has been  superseded by lighter [[Diving helmet#Free-flow helmets|free-flow helmets]], and to a large extent, [[Diving helmet#Lightweight demand helmets|lightweight demand helmets]], [[Full face diving mask#Band masks|band masks]] and [[full-face diving mask]]s. [[Breathing gas]]es used include [[air]], [[heliox]], [[nitrox]] and [[Trimix (breathing gas)|trimix]].

[[Saturation diving]] is a mode of surface supplied diving in which the divers live under pressure in a [[Saturation diving#Architecture of a surface saturation facility|saturation system]] or [[underwater habitat]] and are [[Decompression (diving)|decompressed]] only at the end of a tour of duty.

Air-line, or hookah diving, and "[[compressor diving]]" are lower technology variants also using a breathing air supply from the surface.

== Variations ==
There are two basic modes of surface-supplied diving, and several variations for supplying breathing gas to divers from the surface.

===Surface oriented diving===
<!-- target of redirect [[Surface oriented diving]] -->
Surface oriented diving, with or without a stage or open bell, is where the diver starts and ends the dive at surface pressure. The diver is decompressed during the ascent or by [[surface decompression]] in a decompression chamber.<ref name="Beyerstein" /> It may also be referred to as [[bounce diving]], an ambiguous term.

In addition to the standard system of surface-supplied diving using a diver's umbilical and diving helmet or full-face diving mask to provide the diver with compressed atmospheric air from a low-pressure diving compressor, there are other configurations in use for surface oriented diving:

Technically, [[atmospheric suit diving]], [[scuba diving]] and [[freediving]] are also "surface oriented", but are not "surface-supplied".

====Scuba replacement====
<!-- target of redirect [[Scuba replacement]] -->
Scuba replacement is a surface-supplied diving mode where both the primary and reserve breathing gas supplies are from high-pressure storage cylinders. The rest of the system is identical to the standard surface supply configuration, and the full umbilical system, bailout cylinder, communications and surface gas panel are used. This is more portable than most compressors and is used by commercial diving contractors as a substitute for scuba with most of the advantages and disadvantages of a regular compressor fed surface air supply.<ref name="IMCAD022" />{{rp|149}} It is also used where the ambient air is contaminated and unsuitable for use as a breathing gas when compressed, such as some situations in [[hazmat diving]].<!-- <ref name="Barsky" /> Check ref -->

====Standard diving dress====
{{main|Standard diving dress}}
Standard, or heavy gear is the historical copper helmet, waterproofed canvas suit, and weighted boots. The original system used a manually powered [[diver's pump]] to supply air, and no reserve gas or bailout cylinder was provided. As the technology became available, voice communication was added, and mechanically driven compressors were used.<ref name="USNDM R1" />

====Air-line diving====
<!-- target for reditect [[Hookah diving]] -->
Air-line diving uses an [[air line]] hose in place of a full [[diver's umbilical]] to supply breathing air from the surface. If any of the required components of a diver's umbilical are absent this term applies. There are subcatgories of air-line diving:
* [[Hookah diving]] – A basic form of surface-supplied diving in which the air supply is via a single hose is often referred to as air line or Hookah (occasionally Hooka) diving. This often uses a standard scuba second stage as the delivery unit, but is also used with light full-face masks.<ref name="Barsky and Neuman 2003" />{{rp|29}} Bailout gas may be carried, but this is not always the case. Commercial diamond divers working in the shallow zone off the west coast of South Africa under the codes of practice of the [[Department of Minerals and Energy]] use half mask and demand valve hookah. Their safety record is relatively poor, as a [[bailout cylinder]] is seldom carried. {{citation needed|date=October 2011}} When done using a diving compressor with suitable breathing air quality and an appropriate emergency gas supply, there is no obvious reason why hookah diving should be more dangerous than scuba diving in the same conditions. A concern is that if the diver is supplied from a compressor in a boat, the intake must be clear of any exhaust fumes, which is also the case for surface supplied diving using a full umbilical.<ref name="scubadoc hookah" />
* [[Snuba]] and [[SASUBA]] – A system used to supply air from a cylinder mounted on a float to a recreational diver tethered by a short (approximately 6&nbsp;m) hose through a scuba regulator.<ref name="seattle1995" />
* [[#Compressor diving|Compressor diving]] – An even more basic system is the "Compressor diving" arrangement used in the Philippines and Caribbean for fishing. This rudimentary and highly hazardous system uses a large number of small bore plastic tubes connected to a single compressor to supply a large number of divers simultaneously. The delivery end of the hose is unencumbered by any mechanism or mouthpiece, and is simply held by the diver's teeth. Air supply is free flow and often unfiltered, and varies with depth and number of divers drawing off the system, with greater flow going to divers with a shorter hose and at shallower depth. A kink or restriction in a hose can cut off a diver's air supply without warning.<ref name="Into the blue" />

====Bell bounce diving====
<!-- Target from redirect [[Bell bounce diving]] -->
{{See also|Surface-supplied diving skills#Bell bounce diving}}
Bell bounce diving, also known as transfer under pressure diving, is where the divers are transported vertically through the water in a [[closed bell]] and [[Transfer under pressure|transferred under pressure]] into a surface [[Deck decompression chamber|decompression chamber]] for decompression, or decompressed in the bell. This mode of diving is most likely to be used when the dive is relatively deep, and the decompression is likely to be long, but neither deep enough nor long enough to justify the costs of setting up for saturation diving. The mode was often used with mixed breathing gases.<ref name="Beyerstein" /> but is also used for long air dives shallower than 50 m.<ref name="TUP" />

A development of this system uses a set of decompression chambers mounted in a lifeboat for the routine surface decompression of the divers. The lifeboat is positioned between the transfer chamber and the side of the deck, and can be launched by the davits included in the package. This avoids the necessity for an additional [[hyperbaric evacuation system]].<ref name="SPAS" />

===Saturation diving===
{{main|Saturation diving}}
In saturation diving, the diver is transferred under pressure from the pressurised accommodation to the underwater worksite, which is at a similar pressure, and back in a closed bell, only decompressing once at the end of the contract.<ref name="Beyerstein" />

===Open, closed, and semi-closed circuit systems===
{{See also|Diving rebreather|Diving regulator|Gas reclaim system|Gas extender}}
<!--target for redirect from [[Open-circuit surface-supplied diving]] -->
The surface-supplied diving mode can be further qualified by the management of exhaled and bypassed breathing gas. In open-circuit mode it is discharged directly into the ambient environment. In semi-closed or gas-extender mode, it is partly recirculated and scrubbed to remove carbon dioxide, and partly replenished to maintain an acceptable oxygen partial pressure., with the balance discharged to the ambient environment. In closed circuit and gas reclaim systems, most to all of the gas is scrubbed, re-oxygenated, and made available for either immediate or later re-use. Full or partial recycling is usually used to make more economical use of helium based gases due to the high cost of helium and the large quantities used at the depths where it is needed.{{cn|date=October 2025}}

{{expand section|date=October 2025}}

== Alternatives ==
Alternative modes of diving may be used to attain the objectives of a surface-supplied dive in some circumstances:
* [[Scuba diving]], which is commonly used for [[recreational diving]] and [[scientific diving]], is the main alternative to surface-supplied diving. Scuba is available in open circuit and [[rebreather]] configurations.<ref name="NOAA 4th Ed" />
* [[Atmospheric diving suit]]s such as the [[JIM suit]] and the [[Newtsuit]], and manned submersibles with manipulator arms, isolate the occupant from the ambient pressure, but are bulky, expensive, and allow limited dexterity and agility.<ref name="Offshore" />
* Unmanned [[submersible]]s ([[remotely operated underwater vehicle|ROVs]] and [[Autonomous underwater vehicle|AUVs]]) which can operate deeper and avoid exposing a diver to underwater hazards, have their applications, but lack the dexterity of a diver at present (2011).<ref name="Offshore" />
* [[Freediving]], or breathhold diving, is extremely limited in duration and exposes the diver to relatively high risk.<ref name="Gilliam 2014">{{cite web|url=https://divermag.com/the-hazards-of-freediving/ |title=The Hazards of Freediving |website=divermag.com |first=Bret |last=Gilliam |access-date=15 October 2025 |date=27 October 2014 }}</ref><ref name="Lindholm 2006" >{{cite conference|url=https://www.diversalertnetwork.org/files/UHMS_DAN_2006_Breath-hold_Workshop_Proceedings.pdf|last=Lindholm |first=Peter |title=Physiological mechanisms involved in the risk of loss of consciousness during breath-hold diving |editor1-last=Lindholm |editor1-first=P. |editor2-last=Pollock |editor2-first=N. W. |editor3-last=Lundgren |editor3-first=C.E.G.|year=2006|work=Breath-hold diving. Proceedings of the Undersea and Hyperbaric Medical Society/Divers Alert Network 2006 June 20–21 Workshop.|publisher=Divers Alert Network |page=26 |access-date=24 January 2017|location=Durham, NC |isbn=978-1-930536-36-4 }}</ref><ref name="Pollock 2014" >{{cite web |url=http://ndpa.org/loss-of-consciousness-in-breath-holding-swimmers/ |title=Loss of Consciousness in Breath-Holding Swimmers |last=Pollock |first=Neal W. |date=25 April 2014 |work=Fact Sheets, Water Safety |publisher=National Drowning Prevention Alliance (NDPA.org) |access-date=17 January 2017 |archive-url=https://web.archive.org/web/20170202024452/http://ndpa.org/loss-of-consciousness-in-breath-holding-swimmers/ |archive-date=2 February 2017 |url-status=dead }}</ref>

== Application ==
[[File:Scaphandrier en milieu pollué - casque aquadyne ah3.JPG|thumb|Free flow helmets are commonly used for diving in contaminated water]]
Surface-supplied diving equipment and techniques are mainly used in [[professional diving]] due to the greater cost and complexity of owning and operating the equipment.<ref name=Beyerstein /><ref name="Wilkins 2006" /> This type of equipment is used in [[saturation diving]], as the gas supply is relatively secure, and the diver can not bail out to the surface,<ref name=Beyerstein /> and for diving in contaminated water, where the diver must be protected from the environment, and helmets are generally used for environmental isolation.<ref name="Barsky" />

A major limitation of surface-supplied diving is the presence of an umbilical between the surface control point and the diver, which encumbers the diver's mobility, restricts their range of access to the environment, and requires an attendant to manage the umbilical,<ref name="Tennessee aquarium" /> which can get snagged on underwater obstructions even when correctly tended.<ref name="IMCA SF15/09" /> Where this limitation is acceptable, the connection with the diver provides some advantages, in that the diver can find their way back to the control point by following the umbilical, and a standby diver can reach the diver by following the umbilical.<ref name="Tennessee aquarium" />

There has been development of low-cost airline systems for shallow recreational diving, where limited training is offset by physically limiting the depth accessible.<ref name="seattle1995" />

There are two major advantaged to surface supplied diving: The breathing gas supply is not limited to the ability of the diver to carry it, and is monitored from the surface, reducing the task load on the diver, and the diver is in continuous communication with the surface control point, so their safety can be monitored effectively. The physical constraint of the umbulical is sometimes a limitation on mobility and radius of activity, and at other times a safety feature, preventing access to known hazards and identifying the route back to a place of safety.<ref name="IMCACoP" />

{{expand section|advantages and limitations|date=June 2025}}

==History==
{{see|Standard diving dress#History|Diving helmet#History|History of underwater diving|}}
[[File:Deane helmet 1842.jpg|thumb|right|1842 sketch of the Deane brothers' diving helmet, the first surface-supplied diving dress equipment in the world.]]

The first successful surface-supplied diving equipment was produced by the brothers [[Charles Anthony Deane|Charles]] and [[John Deane (inventor)|John Deane]] in the 1820s.<ref name="Bevan 1966" /> Inspired by an accident John witnessed in a stable in England, during which he rescued several horses from smoke filled stable<ref name="Scuba Ed's" /> they designed and patented a "[[Smoke helmet|Smoke Helmet]]" to be used by firemen in smoke-filled areas in 1823. The apparatus comprised a copper helmet with an attached flexible collar and jacket. A long leather hose attached to the rear of the helmet was to be used to supply air - the original concept being that it would be pumped using a double bellows. A continuous airflow passed through the helmet, and the user breathed from it and exhaled back into it. A short pipe allowed excess air to escape. The garment was constructed from leather or airtight cloth, secured by straps.<ref name="Deane helmet" />

The brothers had insufficient funds to build the equipment themselves, so they sold the patent to their employer, Edward Barnard. It was not until 1827 that the first smoke helmets were built, by German-born British engineer [[Augustus Siebe]]. In 1828 they decided to find another application for their device and converted it into a [[diving helmet]]. They marketed the helmet with a loosely attached "diving suit" so that a diver could perform salvage work but only in a vertical position, otherwise water entered the suit.<ref name="Deane helmet" />

[[File:Divers - Illustrated London News Feb 6 1873-2.PNG|thumb|left|upright|[[Augustus Siebe|Siebe's]] improved design in 1873.]]
In 1829 the Deane brothers sailed from [[Whitstable]] for trials of their new underwater apparatus, establishing the diving industry in the town. In 1834 Charles used his diving helmet and suit in a successful attempt on the wreck of {{HMS|Royal George|1756|6}} at [[Spithead]], during which he recovered 28 of the ship's cannon.<ref name="Divingheritage Deane" /> In 1836, John Deane recovered timbers, guns, longbows, and other items from the rediscovered ''[[Mary Rose]]'' shipwreck.<ref name="Clabby 2014" />
By 1836 the Deane brothers had produced the world's first diving manual, ''Method of Using Deane's Patent Diving Apparatus'' which explained in detail the workings of the apparatus and pump, plus safety precautions.<ref name="Historical diver 1995" />

In the 1830s the Deane brothers asked Siebe to apply his skill to improve their underwater helmet design.<ref name=acott /> Expanding on improvements already made by another engineer, George Edwards, Siebe produced his own design; a [[diving helmet|helmet]] fitted to a full-length watertight [[canvas]] [[diving suit]].<ref name="Dekker Siebe" /> The success of the Siebe helmet was due to an exhaust [[non-return valve]], which prevented flooding through the exhaust port.<ref name="Brylske">{{cite web |url=https://dtmag.com/thelibrary/a-brief-history-of-diving-free-divers-bells-and-helmets/ |title=A Brief History of Diving: Free Divers, Bells and Helmets |website=dtmag.com |date= |access-date=15 October 2025 |first=Alex |last=Brylske }}</ref>

Siebe introduced various modifications on his diving dress design to accommodate the requirements of the salvage team on the wreck of HMS ''Royal George'', including making the helmet be detachable from the [[Standard diving dress#Corselet|corselet]]; his improved design gave rise to the typical [[standard diving dress]] which revolutionised [[underwater]] [[civil engineering]], underwater [[Marine salvage|salvage]], [[commercial diving]] and [[naval diving]].<ref name=acott/>

{{expand section|Stages and bells, mixed gases, lightweight demand helmets, saturation diving, etc. |date=June 2025}}

==Equipment==
{{Main|Surface-supplied diving equipment}}
{{See also|Diving equipment|Diving support equipment}}
[[File:Commercial diving equipment at Eudi Show 2006 adventurediving.it.jpg|thumb|Surface-supplied commercial diving equipment on display at a trade show]]
[[File:Водолазное снаряжение СВУ-5.jpg|thumb|Diver of the Black Sea Fleet in diving equipment SVU-5]]

The essential aspect of surface-supplied diving is that breathing gas is supplied from the surface, either from a specialised [[diving compressor]], high-pressure cylinders, or both. In commercial and military surface-supplied diving, a backup source of surface-supplied breathing gas should always be present in case the primary supply fails. The diver may also wear a [[bailout cylinder]] which can provide self-contained breathing gas in an emergency. Thus, the surface-supplied diver is less likely to have an "out-of-air" emergency than a scuba diver using a single gas supply, as there are normally two alternative breathing gas sources available. Surface-supplied diving equipment usually includes communication capability with the surface, which enhances the safety and efficiency of the working diver.<ref name=Ward2006 />

The equipment needed for surface supplied diving can be broadly grouped as diving and support equipment, but the distinction is not always clear. Diving support equipment is the equipment used to facilitate a diving operation. It is either not taken into the water during the dive, such as the gas panel and compressor, or is not integral to the actual diving, being there to make the dive easier or safer, such as a surface decompression chamber. Some equipment, like a [[diving stage]], is not easily categorised as diving or support equipment, and may be considered as either.

Surface-supplied diving equipment is required for a large proportion of the commercial diving operations conducted in many countries, either by direct legislation, or by authorised codes of practice, as in the case of IMCA operations.<ref name=IMCACoP /> Surface-supplied equipment is also required under the [[United States Navy|US Navy]] operational guidance for diving in harsh [[Water pollution|contaminated environments]] which was drawn up by the [[United States Navy Experimental Diving Unit|Navy Experimental Diving Unit]].<ref name=USNcontam />

===Breathing apparatus===
The definitive equipment for surface-supplied diving is the breathing apparatus which is supplied with primary breathing gas from the surface via a hose, which is usually part of a diver's umbilical connecting the surface supply systems with the diver, sometimes directly, otherwise via a bell umbilical and bell panel.<ref name="Barsky" />

====Helmets====
{{main|diving helmet}}
[[File:Diver Rose Bay 1938 SLNSW FL19114501.jpg|thumb|Diver at Rose Bay, Sydney Harbour, 1938]]
[[Lightweight demand helmet]]s are rigid structures which fully enclose the head of the diver and supply breathing gas "on demand". The flow of gas from the supply line is activated by inhalation reducing the pressure in the helmet to slightly below ambient, and a diaphragm in the demand valve uses this pressure difference to open the valve allowing breathing gas to flow into the helmet until the pressure inside the helmet again balances the ambient pressure and the lever returns to the shut position. This is exactly the same principle as used for scuba demand valves, and in some cases the same components are used. Sensitivity of the lever can often be adjusted by the diver by turning a knob on the side of the demand valve.<ref name="Barsky" />

Lightweight demand helmets are available in open circuit systems which exhaust to the surrounding water, used when breathing standard air or nitrox,<ref name="NOAA 4th Ed" />{{rp|Ch4}} and closed circuit (reclaim) systems used to reduce costs when breathing mixed gas with a large helium fraction.  the exhaled gas is returned to the surface through a reclaim valve, a type of [[back-pressure regulator]] in the helmet, via the umbilical, scrubbed of [[carbon dioxide]], filtered of odour and micro-organisms, re-oxygenated, and recompressed to storage.<ref name="CDM 9" /><ref name="Ahlen 1995" /><ref name="Gasmizer" /><ref name="Crawford 2016" />

The helmet shell may be of metal<ref name="KM77" /> or reinforced plastic composite (GRP), and is either connected to a neck dam or clamped directly to a drysuit. The neck dam is on the lower part of the helmet, which seals around the neck of the diver in the same way as the neck seal of a dry suit. Attachment to the neck dam is critical to diver safety and a reliable locking mechanism is needed to ensure that it is not inadvertently released during a dive.<ref name="Barsky" />

Demand breathing systems reduce the amount of gas required to adequately ventilate the diver, as gas is only supplied when the diver inhales, but the slightly increased work of breathing caused by this system is a disadvantage at extreme levels of exertion, where free-flow systems may be better. The demand system is also quieter than free-flow, particularly during the non-inhalation phase of breathing. This can make voice communication more effective. The breathing of the diver is also audible to the surface team over the communications system, and this helps to monitor the condition of the diver and is a valuable safety feature.<ref name="CDM 9" />

[[File:AH3 free flow helmet front viewDSC01101.jpg|thumb|Front view of an AH3 free flow diving helmet]]
A [[free-flow diving helmet]] supplies a continuous flow of air to the diver, who breathes it as it flows past. Mechanical work of breathing is minimal, but flow rate must be high if the diver works hard, and this is noisy, affecting communications and requiring hearing protection to avoid damage to the ears. This type of helmet is popular where divers have to work hard in relatively shallow water for long periods. It is also useful when diving in contaminated environments, where the helmet is sealed onto a dry suit, and the entire system is kept at a slight positive pressure by adjusting the back-pressure of the exhaust valve, to ensure that there is no leakage into the helmet. This type of helmet is often large in volume, and if it is attached to the suit, it does not move with the head. The diver must move their body to face anything they want to see. For this reason the faceplate is large and there is often an upper window or side windows to improve the field of vision.<ref name="Barsky and Christensen" /><!--Chapter 6: Commercial diving equipment-->

[[File:Escafandra01.JPG|thumb|Copper diving helmet with threaded connection between bonnet and corselet]]
The [[standard diving helmet]] (Copper hat) is made of two main parts: the bonnet, which covers the diver's head, and the corselet which supports the weight of the helmet on the diver's shoulders, and is clamped to the suit to create a watertight seal. The bonnet is attached and sealed to the corselet at the neck, either by bolts or an interrupted screw-thread, with some form of locking mechanism.<ref name="USN 1963" />

[[Image:Standard diving dress 1.jpg|thumb|left|Diver in standard dress entering the water]]
The bonnet is usually a copper shell with soldered [[brass]] fittings. It covers the diver's head and provides sufficient space to turn the head to look out of the glazed faceplate and other viewports (windows). The front port can usually be opened for ventilation and communication when the diver is on deck, by being screwed out or swung to the side on a hinge. The other viewports are generally fixed.<ref name="USN 1963" /><ref name="Denayrouze 2" /><ref name="USN 1943" />

[[File:Gradbišče hidroelektrarne Ožbalt 1958, potapljača.jpg|thumb|Corselet showing interrupted thread for helmet connection and brailes clamping it to the suit. 12-bolt in background, 6-bolt in foreground.]]
The corselet, also known as a breastplate or [[gorget]], is an oval or rectangular collar-piece resting on the shoulders, chest and back, to support the helmet and seal it to the suit.<ref name="Draegerwerk" /> The helmet is usually connected to the suit by clamping the rubberised collar of the suit to the rim of the corselet to make a  water-tight seal. Most six and twelve bolt bonnets are joined to the corselet by 1/8th turn interrupted thread with a safety lock.<ref name="USN 1963" /><ref name="USN 1943" />

An alternative method is to bolt the bonnet to the corselet over a rubber collar seal bonded to the neck opening of the suit.<ref name="Draegerwerk" />

====Band mask====
{{see also|Full face diving mask#Band masks}}
A band mask is a heavy duty full-face mask with many of the characteristics of a lightweight demand helmet. In structure it is the front section of a lightweight helmet from above the faceplate to below the demand valve and exhaust ports, including the bailout block and communications connections on the sides. This rigid frame is attached to a neoprene hood by a metal clamping band, hence the name. It is provided with a padded sealing surface around the frame edge which is held firmly against the diver's face by a rubber "spider", a multiple strap arrangement with a pad behind the diver's head, and usually five straps which hook onto pins on the band. The straps have several holes so the tension can be adjusted to get a comfortable seal. A band mask is heavier than other full face masks, but lighter than a helmet, and can be donned more quickly than a helmet. They are often used by the standby diver for this reason.<ref name="UWC 2014" />

====Full-face mask====
{{main|Full-face mask}}[[Image:Full face diving mask - ocean reef.JPG|thumb|A diver wearing an Ocean Reef full face mask]]
A full-face mask encloses both mouth and nose, which reduces the risk of the diver losing the air supply compared to a half mask and demand valve. Some models require a bailout block to provide alternative breathing gas supply from the umbilical and bailout cylinder, but are not suitable for accepting an alternative air supply from a rescue diver, while a few models accept a secondary demand valve which can be plugged into an accessory port (Draeger, Apeks and Ocean Reef).<ref name="Draeger 2016" /><ref name="Neptune II" /> The unique Kirby Morgan 48 SuperMask has a removable DV pod which can be unclipped to allow the diver to breathe from a standard scuba demand valve with mouthpiece.<ref name="M-48" />

Despite the improvement in diver safety provided by the more secure attachment of the breathing apparatus to the diver's face, some models of full face mask can fail catastrophically if the faceplate is broken or detached from the skirt, as there is then no way to breathe from the mask. This can be mitigated by carrying a standard secondary second stage, and preferably also a spare half mask.<ref name="DiveN2Life" />

A full face mask is lighter and more comfortable for swimming than a helmet or band mask, and usually provides an improved field of vision, but it is not as secure, and does not provide the same level of protection as the heavier and more sturdily constructed equipment. The two types of equipment have different ranges of application. Most full face masks are adaptable for use with scuba or surface supply. The full face mask does not usually have a bailout block fitted, and this is usually attached to the diver's harness, with a single hose to supply the mask from main or bailout gas which is selected at the block. The strap arrangement for full face masks is usually quite secure, but not as secure as a bandmask or helmet, and it is possible for it to be dislodged in the water. However it is also quite practicable for a trained diver to replace and clear a full face mask under water without assistance, so this is more an inconvenience than a disaster unless the diver is rendered unconscious at the same time.<ref name="DiveN2Life" />

===Breathing gas supply===

====Diver's umbilical====
{{see also|Umbilical cable#Divers}}
[[File:Bell umbilical section 20151203 132411.jpg|thumb|Bell umbilical section, containing among other components, hot water supply hoses.]]
The umbilical contains a hose to supply the breathing gas and usually several other components. These usually include a communications cable (comms wire), a [[pneumofathometer]], and a strength member, which may be the breathing gas hose, communications cable, or a rope. When needed, a hot water supply line, helium reclaim line, video camera and lighting cables may be included. These components are neatly twisted into a multistrand cable, or taped together, and are deployed as a single unit. The diver's end has underwater connectors for the electrical cables, and the hoses are usually connected to the helmet, band mask, or bailout block by [[JIC fitting]]s. A [[Carabiner#Locking|screw-gate carabiner]] or similar connector is provided on the strength member for attachment to the diver's harness, and may be used to lift the diver in an emergency. Similar connections are provided for attachment to the diving bell, if used, or to the surface gas panel and communications equipment. A diver's umbilical supplied from a bell gas panel is called an excursion umbilical, and the supply from the surface to the bell panel is the bell umbilical.<ref name=CDM/><ref name="IMCA D022 2016" />

====Air-line====
<!-- target for redirect [[Hookah (diving)]] -->
[[File:Low pressure breathing air compressor P8160075.jpg|thumb|left|Low pressure breathing air compressor intended for air-line diving]]
[[File:Hookah mask PA268055.jpg|thumb|A lightweight full face mask used with a free-flow air-line system (obsolescent)]]
[[File:Hookah mask PA268064.jpg|thumb|Inside view of a lightweight free-flow air-line mask (obsolescent)]]
Hookah, {{Diving term|Sasuba}} and [[Snuba]] systems are categorised as "air-line" equipment, as they do not include the communication, lifeline and pneumofathometer hose characteristic of a full diver's umbilical. Most hookah diving uses a demand system based on a standard scuba second stage, but there have been special purpose free-flow full-face masks specifically intended for hookah diving (see photos). A [[Bailout cylinder|bailout system]], or emergency gas supply (EGS) is not an inherent part of an air-line diving system, though it may be required in some applications.<ref name="FAO Hookah" /><ref name="scubadoc hookah" />

Their field of application is very different from full surface-supplied diving. Hookah is generally used for shallow water work in low-hazard applications, such as archaeology, aquaculture, and aquarium maintenance work, but is also sometimes used for open water hunting and gathering of seafood,<ref name="FAO Hookah" /> shallow water mining of gold and diamonds in rivers and streams, and bottom cleaning and other underwater maintenance of boats, hull cleaning, swimming pool maintenance, and shallow underwater inspections.<ref name="Barsky and Neuman 2003" />{{rp|29}} Sasuba and Snuba are mainly a shallow water recreational application for low-hazard sites.<ref name="seattle1995" />

The systems used to supply air through the hose to a demand valve mouthpiece, are either 12-volt electrical air pumps, gasoline engine powered low-pressure compressors, or floating scuba cylinders with high pressure regulators. These hookah diving systems usually limit the hose length to allow less than 7 metres depth.<ref name="seattle1995" /> The exception is the gasoline engine powered unit, which requires a much higher level of training and topside supervision for safe use.<ref name="FAO Hookah" />

A notable exception to this trend are the inshore diamond diving operations on the west coast of South Africa, where hookah is still the standard equipment for diamondiferous gravel extraction in the hostile conditions of the surf zone, where the water temperature is usually around 8 to 10&nbsp;°C, visibility is usually low, and {{Diving term#surge|surge}} is often strong. Divers work shifts of about two hours with a crowbar and a suction hose, are heavily weighted to stay in place while working, and the standard method of ascent is to ditch the weighted harness and regulator and make a free swimming ascent. The next diver will free dive down the air line, fit the regulator and wriggle into the harness before continuing with the job.{{Citation needed|date=September 2016}} Until the South African abalone fishery was closed, hookah was the only mode of diving permitted for harvesting wild abalone.{{cn|date=October 2025}}

====Gas panel====
<!-- target for redirect [[Gas panel]] -->
[[File:Surface supply air panel for 4 divers P3053737.jpg|thumb|left|A surface supply panel for four divers. This panel can use an independent gas supply for each side of the panel]]
[[File:Air panels and comms box at a surface supplied diver training operation P3118538.jpg|thumb|Surface supply air panels. On the left for two divers, on the right for three divers]]
[[File:Gas panel 1.png|thumb|Surface supplied diving gas panel for one diver:
{{unbulleted list|PG: pneumofathometer gauge |OPV: overpressure valve |PS: pneumo snubber |PSV: pneumo supply valve |DSV: diver supply valve |MP: manifold pressure |RSV: reserve supply valve |RP: reserve pressure |MSV: main supply valve |SP: supply pressure |RGS: reserve gas supply |MGS: main gas supply |UP: umbilical pneumo hose |UB: umbilical breathing gas hose |DP: depth measured by pneumofathometer }}]]
A gas panel or gas manifold is the control equipment for supplying the breathing gas to the divers.<ref name="Barsky and Christensen" /> Primary and reserve gas is supplied to the panel through shutoff valves from a low-pressure compressor or high-pressure storage cylinders ("bombs", "bundles", "quads", or "kellys"). The gas pressure may be controlled at the panel by an industrial [[pressure regulator]], or it may already be regulated closer to the source (at the compressor, or at the storage cylinder outlet). The supply gas pressure is monitored on a gauge at the panel, and an over-pressure valve is fitted in case the supply pressure is too high. The gas panel may be operated by the diving supervisor if the breathing gas is air or a fixed ratio premix, but if the composition must be controlled or monitored during the dive it is usual for a dedicated gas panel operator, or "gas man" to do this work.<ref name=CDM/>

There is a set of valves and gauges for each diver to be supplied from the panel. These include:<ref name=CDM/>
* A main supply valve with non-return valve, which supplies gas to the main gas supply hose of the umbilical. This is usually a quarter-turn valve, as it must be quick to operate and obvious whether it is open or closed.<ref name=CDM/>
* A pneumofathometer supply valve, which supplies gas to the pneumofathometer for the diver. This valve is usually near the main supply valve but with a different handle. It is usually a needle type valve as it must be finely adjustable, but it must also be large enough to allow a fairly high flow rate, as the air may be used as an alternative breathing air source, or to fill small lift bags.<ref name=CDM/>
* A pneumofathometer gauge is connected to the pneumo line. This is a high resolution pressure gauge calibrated in feet sea water (fsw) and/or metres sea water (msw). and is used to measure the depth of the diver by allowing air to flow through the pneumo hose and out the end attached to the diver. When the air supply is shut off, and the flow stops, the gauge indicates the pressure at the open end at the diver.<ref name=CDM/>
* Each pneumofathometer gauge has an overpressure valve to protect it against gas supply at higher pressure than it is designed to take. This is essential as the main supply pressure is significantly higher than the maximum depth pressure on the pneumo gauge. There is also often a snubbing valve or orifice between the pneumo line and the gauge to restrict flow into the gauge and ensure that the overpressure valve can adequately relieve the pressure.<ref name=CDM/>
* Some gas panels have a separate supply gauge for each diver downstream of the supply valve, but this is not standard practice.<ref name=CDM/>
The gas panel may be fairly large and mounted on a board for convenience of use, or may be compact and mounted inside a portable box, for ease of transport. Gas panels are usually for one, two or three divers. In some countries, or under some codes of practice, the surface standby diver must be supplied from a separate panel to the working diver/s.<ref name="OSO 2011" />

A wet or closed bell will be fitted with a bell gas panel to supply gas to the divers' excursion umbilicals. The bell gas panel is supplied with primary gas from the surface via a bell umbilical, and on-board emergency gas from high-pressure storage cylinders mounted on the frame of the bell.<ref name="IMCAD022" /><ref name="IMCA D014" />

===== Pneumofathometer =====
A ''[[pneumofathometer]]'' is a device used to measure the depth of a diver by displaying the back-pressure on a gas supply hose with an open end at the diver, and a flow rate with negligible resistance in the hose. The pressure indicated is the hydrostic pressure at the depth of the open end, and is usually displayed in units of [[Metre sea water|metres or feet of seawater]], the same units used for decompression calculations.<ref name="CDM" />

The pneumo line is usually a {{convert|0.25|inch|mm}} bore hose in the diver's umbilical, supplied with breathing gas from the gas panel via a supply valve. Downstream from the valve there is a branch to a high resolution pressure gauge, a restriction to flow to the gauge, and an overpressure relief valve to protect the gauge from full panel supply pressure in case the pneumo line is used for emergency breathing gas supply. Each diver has an independent pneumofathometer, and if there is a bell, it will also have an independent pneumofathometer.<ref name="CDM" />

====Low-pressure breathing air compressor====
[[File:Low pressure breathing air compressor P3118541.jpg|thumb|A low-pressure compressor on site providing breathing air for surface-supplied divers]]
A low-pressure compressor is often the air supply of choice for surface-supplied diving, as it is virtually unlimited in the amount of air it can supply, provided the delivery volume and pressure are adequate for the application. A low-pressure compressor can run for tens of hours, needing only refueling, periodical filter drainage and occasional running checks, and is therefore more convenient than high-pressure storage cylinders for primary air supply.<ref name=CDM />

However, it is critical to diver safety that the compressor is suitable for breathing air delivery, uses a suitable oil, is adequately filtered, and takes in clean and uncontaminated air. Positioning of the intake opening is important, and may have to be changed if the relative wind direction changes, to ensure that no engine exhaust gas enters the intake. Various national standards for breathing air quality may apply.{{cn|date=October 2025}}

Power for portable compressors is usually a 4-stroke petrol (gasoline) engine. Larger, trailer mounted compressors, may be diesel powered. Permanently installed compressors on [[diving support vessel]]s are likely to be powered by 3-phase [[electric motor]]s.{{cn|date=October 2025}}

The compressor should be provided with an accumulator and a relief valve. The accumulator functions as an additional water trap, but the main purpose is to provide a reserve volume of pressurised air. The relief valve allows any excess air to be released back to the atmosphere while retaining the appropriate supply pressure in the accumulator.<ref name=CDM/>

====High pressure main gas supply====
{{see also|Saturation diving#Bulk gas supplies}}
The main gas supply for surface-supplied diving can be from high pressure bulk storage cylinders. When the storage cylinders are relatively portable this is known as a ''scuba replacement'' system in the commercial diving industry. The application is versatile and can ensure high quality breathing gas in places where atmospheric air is too contaminated to use through a normal low pressure compressor filter system, and is easily adaptable to a mixed gas supply and oxygen decompression provided that the breathing apparatus and gas supply system are compatible with the mixtures to be used. Scuba replacement is often used from smaller diving support vessels, for emergency work, and for [[hazmat diving]], where the atmospheric air at the site may be contaminated.<ref name="Barsky" />{{rp|94}}<ref name="Supsalv 2019" />

Mixed breathing gases are provided from high pressure bulk storage systems for saturation diving, but these are less portable, and generally involve manifolded racks of  cylinders of approximately 50 litres water capacity arranged as ''quads'' and even larger racks of high pressure ''tubes''. If [[Saturation diving#Gas reclaim systems|gas reclaim systems]] are used, the reclaimed gas is [[Carbon dioxide scrubber|scrubbed of carbon dioxide]], filtered of other contaminants, and recompressed into high pressure cylinders for interim storage, ans is generally blended with oxygen or helium to make up the required mix for the next dive before re-use.<ref name="Crawford 2016" />

====Decompression gas====
{{see also|Decompression equipment#Providing gases to accelerate decompression|Decompression practice#Accelerated decompression}}
Reducing the partial pressure of the inert gas component of the breathing mixture will accelerate decompression as the concentration gradient will be greater for a given depth. This is achieved by increasing the fraction of oxygen in the breathing gas used, whereas substitution of a different inert gas will not produce the desired effect. Any substitution may introduce counter-diffusion complications, owing to differing rates of diffusion of the inert gases, which can lead to a net gain in total dissolved gas tension in a tissue. This can lead to bubble formation and growth, with decompression sickness as a consequence. Partial pressure of oxygen is usually limited to 1.6 bar during in-water decompression for scuba divers, but can be up to 1.9 bar in-water and 2.2 bar in the chamber when using the US Navy tables for surface decompression,<ref name="US Navy Diving Manual Revision 6 Ch9"/>

====High-pressure reserve gas====
<!--target for Redirect [[Reserve gas supply (diving)]]-->
An alternative to a low-pressure compressor for gas supply is high-pressure storage cylinders feeding through a pressure regulator which will be set to the required supply pressure for the depth and equipment in use. In practice HP storage may be used for either reserve gas supply or both main and reserve gas supplies to a gas panel. High-pressure bulk cylinders are quiet in operation and provide gas of known quality (if it has been tested). This allows the relatively simple and reliable use of nitrox mixtures in surface-supplied diving. Bulk cylinders are also quiet in operation compared to a low-pressure compressor, but have the obvious limitation of amount of gas available.
The usual configurations for surface-supplied bulk gas storage are large single cylinders of around 50 litres water capacity, often referred to as "J"s or "bombs", "[[Gas storage quad|quads]]", which are a group (sometimes, but not necessarily four in number) of similar cylinders mounted on a frame and connected together to a common supply fitting, and "kellys" which are a group of "tubes" (long large volume pressure vessels) usually mounted in a [[Intermodal container|container frame]], and usually connected together to a common connection fitting.<ref name=IMCAD043 />

====Bailout gas supply====
{{main|Bailout cylinder}}

[[File:Bailout block on a KM18 band mask PA268043.jpg|thumb|The bailout block on a KM18 band mask, showing the bailout valve (upper left), the non-return valve for main air supply (lower left), and the free-flow valve (right)]]
Bailout gas is usually carried by the diver in a scuba cylinder, mounted on the back of the harness in the same position as is used with recreational scuba. The size of the cylinder will depend on operational variables. There should be sufficient gas to enable the diver to reach a place of safety on the bailout gas in an emergency. For surface oriented dives, this may require gas for decompression, and bailout sets generally start at about 7 litres internal capacity and can be larger.<ref name="inshore" />

Bell diving bailout options: For bell dives there is no requirement for decompression gas, as the bell itself carries bailout gas. However at extreme depths the diver will use gas fast, and there have been cases where twin 10 litre 300 bar sets were required to supply sufficient gas. Another option which has been used for extreme depth is a rebreather bailout set. A limitation for this service is that the diver must be able to get in and out of the bell while wearing the bailout equipment.{{citation needed|date=September 2016}}

Mounting options: The bailout cylinder may be mounted with the valve at the top or at the bottom, depending on local codes of practice. A generally used arrangement is to mount the cylinder with the valve up, as this is better protected while kitting up, and the cylinder valve is left fully open while the diver is in the water. This means that the regulator and supply hose to the bailout block will be pressurised during the dive, and ready for immediate use by opening the bailout valve on the harness or helmet.<ref name="inshore" />

The bailout block is a small manifold fitted either to the harness where it is in a convenient but protected position, commonly on the right side on the waist strap, or on the helmet, also usually on the right side of the temple, with the valve knob to the side to distinguish it from the free-flow or defogging valve which is commonly to the front. The bailout block has a connection for the main gas supply from the umbilical through a non-return valve. This route can not be closed and supplies the helmet demand valve and free flow valve under normal circumstances. The bailout gas from the back mounted cylinder passes through a conventional scuba first stage at the cylinder valve, to the bailout block, where it is normally isolated by the bailout valve. When the diver needs to switch over to bailout gas he simply opens the bailout valve and the gas is supplied to the helmet or mask. As the valve is normally closed, a leak in the first stage regulator seat will cause the interstage pressure to rise, and unless an overpressure relief valve is fitted to the first stage the hose may burst. Aftermarket overpressure valves are available which can be fitted into a standard low-pressure port of most first stages.<ref name="KM OPRV" />

Bailout supply pressure options: If the interstage pressure for the bailout regulator is lower than the main supply pressure, the main supply will override the bailout gas, and continue to flow. This can be a problem if the diver switches to bailout because main supply is contaminated. If on the other hand, bailout pressure is higher than main supply pressure, the bailout gas will override the main gas supply if the valve is opened. This will result in the bailout gas being used up if the valve leaks. The diver should periodically check that bailout pressure is still sufficient for the rest of the dive, and abort the dive if it is not. For this reason the bailout regulator must be fitted with a submersible pressure gauge to which the diver can refer to check the pressure. This is usually clipped off or tucked into the harness on the left side, where it can be easily reached to read, but is unlikely to snag on anything.{{citation needed|date=September 2016}}

===Diver's harness===
The diver's harness is an item of strong webbing, and sometimes cloth, which is fastened around a diver over the exposure suit, and allows the diver to be lifted without risk of falling out of the harness. Several types are in use.<ref name="Barsky and Christensen" />{{rp|ch6}}<!--Chapter 6: Commercial diving equipment--> 

====Jacket harness====
[[File:Diver harness with weight pocketsPA268054.jpg|thumb|Front view of jacket style diver harness with removable weight pockets]]
The jacket harness is a waistcoat (vest) style garment with strong adjustable webbing straps which are adjustable and securely buckled over the shoulders, across the chest and waist, and through the crotch or around each thigh, so that the diver can not slide out under any predictable circumstance. The harness is fitted with several heavy duty D-rings, fixed to the webbing in such a way that the full weight of the diver and all his equipment can be safely supported. A minimum strength of 500kgf is recommended or required by some codes of practice. A jacket harness is usually provided with webbing straps or a cloth pocket on the back to support the bailout cylinder, and may have a variety of pockets to carry tools, and may also carry ditchable or fixed main weights. There are usually several strong D-rings to secure the umbilical and other equipment.<ref name="CDM 9" />

====Bell harness====
A bell harness has the same function as a jacket harness, but lacks the cloth jacket component, and is made entirely of webbing, with a similar configuration of straps.
It too may have a means of carrying a bailout cylinder, or the bailout cylinder may be carried on a separate backpack.{{citation needed|date=September 2016}}

====Harness with buoyancy compensation====
<!-- target for redirect [[Jump jacket]] -->
The AP Valves Mk4 Jump Jacket is a harness with integral buoyancy jacket specifically designed for commercial diving work with helmets and bells. There is a direct feed to the jacket from the main air supply, from the pneumo line and from bailout, and a system which allows the diver's pneumo to be directly connected to another diver's helmet as an emergency air supply.<ref name="Jones 2008" />

====Buoyancy control====
Surface-supplied divers may be required to work in mid-water or on the bottom. They must be able to stay down without effort, and this usually requires weighting. When working in mid-water the diver may wish to be neutrally buoyant or negative, and when working on the bottom he will usually want to be several kilos negative.
The only time the diver may want to be positively buoyant is when on the surface or during a limited range of emergencies where uncontrolled ascent is less life-threatening than remaining under water. Surface-supplied divers generally have a secure supply of breathing gas, and there are very few occasions where weights should be jettisoned, so in most cases the surface-supplied diver weighting arrangement does not provide for quick release.<ref name="Barsky and Christensen" />{{rp|ch6}}<!--Chapter 6: Commercial diving equipment-->

On those occasions when surface supplied divers need variable buoyancy, it may be provided by inflation of the [[dry suit]], if used, or by a [[buoyancy control device]] similar in principle to those used by [[Scuba diving|scuba divers]], or both.{{citation needed|date=September 2016}}

===Weight systems===
{{main|Diver weighting systems}}
The diver needs to stay on the bottom to work some of the time, and may need to have neutral buoyancy some of the time. The diving suit is usually buoyant, so added weight is usually necessary. This can be provided in several ways. Unwanted positive buoyancy is dangerous to a diver who may need to spend significant time decompressing during the ascent, so the weights are usually attached securely to prevent accidental loss.<ref name="CDM" />

==== Weight belts ====
Weight belts for surface supplied diving are usually provided with buckles which can not accidentally be released, and the weight belt is often worn under the jacket harness.<ref name="Barsky and Christensen" />

==== Weight harnesses ====
When large amounts of weight are needed, a harness may be used to carry the load on the diver's shoulders, rather than around the waist, where it may tend to slip down into an uncomfortable position if the diver is working in a vertical posture, which is often the case. Sometimes this is a separate harness, worn under the safety harness, with pockets at the sides to carry the weights, and sometimes it is an integrated system, which carries the weight in pockets built into or externally attached to the safety harness.<ref name="Barsky and Christensen" />{{rp|ch6}}<!--Chapter 6: Commercial diving equipment-->

==== Trim weights ====
If the diver needs to adjust trim for greater comfort and efficiency while working, trim weights of various types may be added to the harness.

==== Weighted boots ====
Weighted boots of several styles may be used if the diver will be working heavy. Some are in the form of clogs which strap on over the boots, and others use lead inner soles. Ankle weights are also an option, but less comfortable. These weights give the diver better stability when working upright on the bottom, which can significantly improve productivity for some kinds of work.<ref name="USN training" >{{YouTube| 1cwYe9gga9k | "U.S. Navy Standard Deep Sea Diving Outfit training film 43424 NA" }}</ref>

<gallery>
File:Diver Boot- Maritime Museum - Aberdeen-2.jpg|Diver's boot on display at the Aberdeen Maritime Museum
File:Diving safety harness with weight pocketsPA268045.jpg|A diver's safety harness of the jacket type with removable weight pockets, showing the bailout cylinder straps and the webbing strength members with heavy duty D-rings
File:Jacket style diving harness with ditchable weight system DSC01100.jpg|A jacket style diving safety harness with a different ditchable weight system on the side
File:Clip-on diving weight front view DSC04180small.jpg|Clip on trim weights may be attached to the harness webbing to adjust the position of centre of gravity to improve trim
</gallery>

===Environmental protection===
{{main|Diving suit}}
[[Wetsuit]]s are economical and used where the water temperature is not too low - more than about {{convert|65|F|C}}, the diver will not be spending too long in the water, and the water is reasonably clean.<ref name="Barsky and Christensen" />{{rp|ch6}}<!--Chapter 6: Commercial diving equipment-->

[[Dry suit]]s are better thermal protection than most wetsuits, and isolate the diver from the environment more effectively than other exposure suits. When diving in contaminated water, a drysuit with integral boots, sealed dry gloves and a helmet sealed directly to the suit provides the best environmental isolation. The suit material must be selected to be compatible with the expected contaminants. Thermal undersuits can be matched to the expected water temperature.<ref name="Barsky and Christensen" />{{rp|ch6}}<!--Chapter 6: Commercial diving equipment-->

[[Hot water suit]]s provide active warming which is particularly suitable for use with helium based breathing gases. Heated water is provided from the surface through a hose in the umbilical, and water flow can be adjusted to suit the diver's needs. Heated water continuously flows into the suit and is distributed by perforated internal tubes down the front and back of the torso and along the limbs.
<ref name="Barsky and Christensen" />{{rp|ch6}}<!--Chapter 6: Commercial diving equipment-->

The hot water supply hose of the umbilical is commonly {{convert|1/2|in|mm}} bore, and is connected to a supply manifold at the right hip of the suit with a set of valves which allow the diver to control flow to the front and back of the torso, and to the arms and legs, and to dump the supply to the environment if the water is too hot or too cold. The manifold distributes the water through the suit through perforated tubes. The hot-water suit is normally a one-piece neoprene wetsuit, fairly loose fitting, to fit over a neoprene undersuit, which can protect the diver from scalding if the temperature control system fails, with a zipper on the front of the torso and on the lower part of each leg. Gloves and boots are worn which receive hot water from the ends of the arm and leg hoses. If a full-face mask is worn, the hood may be supplied by a tube at the neck of the suit. Helmets do not require heating. The heating water flows out at the neck and cuffs of the suit through the overlap with gloves, boots, or hood.<ref name="PDC manual" />{{rp|ch18}}

===Communications system===
<!--target for redirect [[Communications panel]]-->
{{main|Diver communications}}
[[File:Surface supply diving communications box P3103773.jpg|thumb|left|A hard-wired diver communications unit mounted in a waterproof box for convenience of transport and protection. The loose speaker has been added to increase output volume. there is a built in speaker behind the perforations on the panel]]
[[File:Inside a KM37 diving helmet PA268016.jpg|thumb|Inside a Kirby Morgan 37 helmet showing the microphone in the oro-nasal mask, and one of the speakers at the top of the photo]]
Both hard-wired (cable) and through-water electronic voice communications systems may be used with surface-supplied diving. Wired systems are more popular as there is a physical connection to the diver for gas supply in any case, and adding a cable does not change the handling characteristics of the system. Wired communications systems are still more reliable and simpler to maintain than through-water systems.<ref name="Hardwire" />

====Diver's telephone====
<!--Target for redirect [[Diver's telephone]] -->
The communications equipment is relatively straightforward and may be of the two-wire or four-wire type. Two wire systems use the same wires for surface to diver and diver to surface messages, whereas four wire systems allow the diver's messages  and the surface operator's messages to use separate wire pairs.<ref name="Hardwire" />

In a two wire system the standard arrangement for diver communications is to have the diver's side normally on, so that the surface team can hear anything from the diver at all times except when the surface is sending a message. In a four-wire system the diver's side is always on, even when the surface operator is talking. This is considered an important safety feature, as the surface team can monitor the diver's breathing sounds, which can give early warning of problems developing, and confirms that the diver is alive.<ref name="Hardwire" />

Helium divers may need a decoder system (unscrambler) which reduces the frequency of the sound to make it more intelligible.<ref name="Barsky and Christensen" /><!--Chapter 4: Modes of diving-->{{rp|Ch4}}
{{expand section|more information on diver communications panels|date=September 2024}}
====Video====
Closed circuit video has also become popular, as this allows the surface personnel to see what the diver is doing, which is particularly useful for inspection work, as a non-diving specialist can see the underwater equipment in real time and direct the diver to look at particular features of interest. Closed circuit video is usually helmet mounted along with a helmet mounted video light.<ref name="isubc" >{{cite web |url=https://isubc.com/product-category/diver-closed-circuit-televisions-cctv/ |title=Diver Closed Circuit Televisions (CCTV) |website=isubc.com |access-date=15 October 2025 }}</ref>

====Wireless systems====
Dry bells may have a [[wireless diver communications|through-water]] (wireless) communication system fitted as a backup. This is intended to provide communications in the event that the cable is damaged, or even if the bell is completely severed from the umbilical and deployment cables.<ref name="DSM 1st ed" />

==Equipment maintenance and testing==
All components of a surface supplied diving system are required to be maintained in good working condition for diver safety, and may be required to be tested or calibrated at specified intervals.<ref name="Barsky and Christensen" />{{rp|ch4}}<!--Chapter 4: Modes of diving.-->

==Diving spread==
The diving spread is a commercial diving term for the topside dive site infrastructure supporting the diving operations for a diving project. The diving contractor provides the diving and support equipment and sets it up on site, usually at a place provided for the purpose by the client, or on a diving support vessel. Two types of diving spread are in common use: Air spreads for surface oriented diving operations, where the divers are deployed from normal atmospheric pressure, and decompressed back to atmospheric pressure at the end of the dive, either in-water, or in a chamber for surface decompression, using compressed air as the primary breathing gas, and saturation spreads, where divers are deployed under pressure from the saturation accommodation via a closed diving bell to the underwater worksite, and returned under pressure in the bell to the saturation accommodation system, usually breathing a helium based gas mixture. At the end of their contract the divers are decompressed to surface pressure. The process of selecting, transporting, setting up and testing the equipment is the mobilisation stage of the project, and the demobilisation involves dismantling, transportation and return to storage of the spread components.<ref name="Bluestream" />

Surface oriented mixed gas diving spreads may also be used, but are less common, and are likely to be associated with projects which are too deep for air but require only a short working time at depth.

===Air spread===
An air spread will include the breathing air supply equipment, and often a deck decompression chamber. Where a chamber is present, facilities for hyperbaric oxygen treatment are usually required. If the planned decompression is to be long, a diving stage or bell and the associated handling equipment is likely to be included to allow better control of ascent rate and decompression depth. Equipment for in-water or surface decompression on oxygen (SurDO<sub>2</sub>) may be available.<ref name="inshore" />

Equipment may be necessary to facilitate safe entry to and exit from the water, and may include extrication equipment in case the diver is injured. A basic offshore air diving spread will typically include a dive control unit with compressor and high pressure storage banks, a launch and recovery system with a wet bell, a deck decompression chamber and a hot water unit.<ref name="Bluestream" />

===Saturation spread===
{{see also|Saturation diving#Architecture of a surface saturation facility}}
A saturation spread will include the closed bell and launch and recovery system, saturation habitat, breathing gas supplies and services, all the life support and control equipment, dive equipment stores and workshops, and may also include power supplies and other equipment not directly involved in the diving. It does not include the diving platform as such, for example a DP vessel, or offshore drilling rig, on which the spread is established, or other services such as catering and accommodation for the topside personnel, which would usually be provided to the dive team.<ref name="Thrust" >{{cite web|url=https://www.thrustm.com/saturation-diving |title=Saturation Diving |website=www.thrustm.com |access-date=15 October 2025 }}</ref>

==Diving procedures==
{{main|Surface-supplied diving skills}}
There are a large number of standard procedures associated with surface-supplied diving. Some of these have their equivalents in scuba, and others are very different. Many procedures are common to all surface-supplied diving, others are specific to stage and bell operations or to saturation diving. Details will vary depending on the equipment used, as manufacturers will specify some checks and procedures in detail, and the order may vary to some extent.<ref name="CDM" />

===The working diver===
Preparation of the working diver for the dive is very much a routine, but details depend on the diving equipment and the task, and to some extent on the site, particularly aspects of accessibility.<ref name="CDM" />

==== Preparation for diving ====

Before a diving operation it is usually necessary to set up the surface supply equipment. There are a number of components which must be connected in the correct order, with checks at various stages to ensure that there are no leaks and everything functions correctly. Most diving contractors will have comprehensive checklists that are used to ensure that the equipment is connected in the appropriate sequence and all checks are done. Some checks are critical to the safety of the diver. The compressor must be set up so that it gets uncontaminated air to the intake. Filters should be checked in case they need to be changed. Air supply hoses will be connected to the air panel and checked for leaks, umbilicals connected to the panels and helmets, and the communications equipment connected and tested. Before the umbilical is connected to the helmet or full face mask, the umbilical should be blown through to ensure there is no dirt inside, and the non return valve on the bailout block must be given a function test. This is important, as it is there to prevent backflow of air up the umbilical if the line is cut, and if it fails the diver may suffer a helmet squeeze, or a neck dam flood.<ref name="CDM 9" />

Compared to scuba diving, dressing the diver in{{efn|''Dressing the diver in'' is surface-supplied diving terminology.}} is a relatively laborious process, as the equipment is bulky and fairly heavy, and several components are connected together by hoses. This is more so with helmets, and less so with light full-face masks. It is not usual for the diver to do all the dressing in without the assistance of a diver's tender, who will also manage the umbilical during the dive.<ref name="CDM 9" />
* Exposure suit – The diver will wear an exposure suit appropriate for the planned dive time, breathing gas and water temperature, and also influenced by the level of exertion expected during the dive.<ref name="CDM 9" />
* Harness – After putting on the exposure suit and checking any seals and zips, the diver will put on the harness. The topside crew will usually help as the bailout cylinder will be already mounted, and usually also attached to the helmet, making this a cumbersome procedure, easiest if the diver is seated.<ref name="CDM 9" />
* Weights – The weights will be put onto the diver at some time during the dressing procedure, but the stage where this is done depends on what weighting system is used.<ref name="CDM 9" />
* Bailout – The bailout cylinder is usually strapped to the harness and connected to the helmet before the diver is dressed in.<ref name="CDM 9" />
* Helmet – The helmet is usually put on last, as it is heavy and uncomfortable out of the water. Some divers can put on their own helmet, but it is usual for the topside crew to do most of the locking on to the neck dam, and check that there are no obvious faults with the seal.<ref name="CDM 9" />

There are a series of pre-dive checks which are done after the diver is locked into the helmet, and before he is committed to the water. These should be done every time a diver is prepared for a dive.<ref name="CDM 9" />
* Comms check – The diver and comms operator check that the voice communications system is working both ways and they can hear each other clearly. This also ensures that the operator is sure which comms channel connects to the specific diver.<ref name="CDM 9" />
* Breathing checks – The diver breathes on main air supply to ensure that the demand valve is delivering gas at low work of breathing, without free flow, and that the umbilical is connected to the correct valve on the panel.<ref name="CDM 9" />
* Bailout checks – The diver operates the bailout system to ensure that he can reach and operate the valve and it turns smoothly, the pressure in the cylinder is adequate for the planned dive profile and is ready for immediate use, and reports bailout readiness to the supervisor by "On at the tap, off at the hat, Pressure...bar" or equivalent.<ref name="CDM 9" />

Surface checks are done after the diver enters the water, but before he is allowed to descend. They are checks which can not be done as effectively, or at all, in air.<ref name="CDM 9" />
* Wet comms check – Once in the water, the comms should be checked again to make sure it is still working adequately. It is possible that water will cause the comms to fail or deteriorate when the contacts get wet.<ref name="CDM 9" />
* Helmet seal – The helmet seals and neckdam should not allow water to enter the helmet. This can only be checked when in the water.<ref name="CDM 9" />
* Pneumo bubbles – The diver calls for the air panel operator to open the pneumofathometer valve to check that the line is not blocked, and that it is connected to the correct place on the panel.<ref name="CDM 9" />

====Diving heavy====
The traditional buoyancy condition of the working surface-supplied diver is "heavy", or negatively buoyant, with sufficient apparent weight to move around on the bottom by walking. This was more important with the standard diving dress, where inadvertent positive buoyancy could have fatal consequences if poorly managed and degraded to an uncontrolled buoyant ascent. Diving heavy has advantages for working when there is good footing, as the diver has more natural resistance to the reaction forces on tools used and to light currents, due to friction and ground reaction, so the technique remains popular for many tasks.

The technique virtually eliminates the risk of uncontrolled buoyant ascent, and reduces task loading, but makes the diver dependent on umbilical management or a [[Jackstay (diving)|jackstay]] for depth control in midwater and introduces a risk of accidental descent to unplanned depths by falling off the substrate and sinking until the slack  in the umbilical is taken up, but with an adequate gas supply the risk of serious [[Squeeze (diving)|squeeze]] injury is low.
{{Expand section|date=September 2023}}

====Emergency procedures====
{{further|Surface-supplied diving skills#Emergency procedures}}
The diver must be able to deal with the following emergencies. Some are life-threatening, whereas others are more inconveniences.<ref name="CDM 9" /><ref name="CDM 10" /><ref name="C2DTS" />
* Bailout to back gas, in the case of a failure of gas supply from the umbilical, or if the main air supply is contaminated.
* Pneumo breathing, if the main air supply is cut, but the pneumo hose is intact. Pneumo gas can also be supplied by the standby diver
* Voice communications failure is not usually an emergency, but can adversely affect work effectiveness and expose the diver to higher risk if anything else goes wrong. Ability to communicate with line signals can help here, particularly to assist in the decision whether the dive should be aborted, and if there are other more urgent problems.
* Helmet flood. Depending on the severity of the flood, this can range from an annoyance to an emergency. A slow leak can be controlled by opening the free flow valve, which will drive a moderate flow of water out of the exhaust valve. A neck dam failure usually has this effect.
* Broken faceplate. This is a real emergency, but very unlikely as the faceplate is usually a highly impact-resistant polymer and should not shatter. It can be mitigated by opening the free flow valve and holding the opening level, facing down, and breathing very carefully. a small hole or crack can be covered with a hand to slow the leak.
* Demand valve failure. This is a minor problem if there is a free flow valve, but the dive will normally be terminated, as the bailout will not last long if needed.
* Exhaust valve failure, like demand valve failure, can be dealt with by opening the free flow valve and ensuring a constant outflow of air.
* Vomiting in the helmet. This can be a real emergency and life-threatening in a demand helmet with an orinasal mask if not handled effectively, as the diver can aspirate the vomit and asphyxiate. Once again, the action is to open the free flow valve, preferably before vomiting, and to inhale as carefully as possible. If there is no free flow valve, as on a full face mask, the purge button should clear the demand valve and orinasal mask, and the mask can be rinsed by lifting the bottom edge away from the face to let in some water, before purging again. With a free-flow helmet it is more a nuisance than an emergency.
* Hot water supply failure. This can be life-threatening for deep heliox diving, and there is not much the diver can do but head back to the bell immediately.

====Wet bell and stage emergency procedures====
{{further|Surface-supplied diving skills#Emergency wet bell procedures}}
Emergency procedures for wet bell and diving stages include:<ref name="C2DTS" /><ref name="CDM 11" /><ref name=IMCACoP />
* [[Surface-supplied diving skills#Surface gas supply failure|Loss of main gas supply]] to the bell
* [[Surface-supplied diving skills#Rescue of the working diver|Recovery of a distressed diver]] to the bell
* [[Surface-supplied diving skills#Bell abandonment|Abandonment of the bell or stage]]
* Deployment of a surface standby diver
* [[Surface-supplied diving skills#Hot water supply failure|Loss of heated water supply]] for [[Diving suit#Hot water suits|hot water suits]]
* [[Diver communications#Voice communications|Voice communications]] failures
* [[Dynamic positioning#Dynamic positioning alarm and runout response for bell divers|Dynamic positioning alarm and runout response for bell divers]]: Yellow and Red alerts.

===Standby diver===
<!-- Target from redirect [[Standby diver]], [[Surface stand-by diver procedures]] -->
{{see also|Diving team#Stand-by diver}}
The standby diver will be prepared in the same way as the working diver, but will not enter the water until needed. He will usually be prepared to the stage of readiness to enter the water, and then will remove his mask, or have his helmet removed and will then sit in as comfortable a place as can be found, so that in case of an emergency he can be readied for action in as short a time as possible.<ref name="BuRec dive manual" /> This often means setting up some form of shelter from the weather, and heat and sunshine are usually more of a problem than cold and wet. It is frequently necessary to cool the standby diver to avoid overheating, and dehydration can also be a problem.<ref name="CADC 2015" /> When the working diver is using a helmet, the stand-by diver may use a full face mask or bandmask, as this makes it quicker to get into the water in an emergency. The stand-by diver's job is to wait until something goes wrong, and then be sent in to sort it out. For this reason a stand by diver should be one of the best divers on the team regarding diving skills and strength, but does not have to be expert at the work skills for the specific job. When deployed, the standby diver will normally follow the umbilical of the diver who is in trouble, as unless it has been severed, it will reliably lead to the correct diver. The standby diver must maintain communications with the supervisor throughout the dive and is expected to give a running commentary of progress so that the supervisor and surface crew know as much as possible what is happening and can plan accordingly, and must take the necessary steps to resolve incidents, which may involve supply of emergency air or locating and rescuing an injured or unconscious diver. In bell diving, the bellman is the primary standby diver, and may have to recover a distressed diver to the bell and give first aid if necessary and possible. There will generally also be a surface standby diver in a bell operation, as some types of assistance are provided from the surface.<ref name="Standby diver" /><ref name=IMCACoP /><ref name="SSBA Standby" />

A rescue tether or rescue strop is a short length of rope or webbing with a clip at one or both ends, which the stand-by diver uses to clip the unresponsive diver to his harness to free up both hands during a recovery. This can be useful if he needs to climb a structure, shotline or topographical feature, and the umbilicals can not be safely used to lift the divers due to snags or sharp edges.<ref name="SSBA Standby" />

=== Bellman ===
{{See also|Diving team#Bellman}}
A bellman is a stand-by diver who tends the working diver's umbilical from a wet or closed bell, and is ready to go to the diver's assistance at all times. The bellman must be in effective voice communication with the supervisor.<ref name="IMCA D022 2016" />

===Underwater tending point===
<!--Target for [[Underwater tending point]]-->
For some operations it is necessary to control the umbilical at a point underwater. This is known as an underwater tending point, and it may be done by another diver or by the diver passing through a closed [[fairlead]] placed in the required position. This is usually done to prevent inadvertent access to a known hazard by making the length of the umbilical extending beyond the tending point too short to let the diver get to the hazard. The fairlead must constrain the umbilical laterally and vertically, while allowing free passage away from and back to the bell or stage, and should not interfere with the bellman's ability to pay out or take up slack when the diver travels to the workplace and back. It may be held in position by suspending a weighted hoop from a crane, resting a frame on the bottom, or other methods as may suit the job. Underwater tending may also be used for penetrations of enclosed spaces, such as wrecks, caves, penstocks, sewers, culverts and the like. A diving stage or basket is a by default an underwater tending point, as the umbilical passes through it from the surface to the diver, which also serves as a guide line for the diver to get back to the stage. A diving bell is also an underwater tending point, as the [[excursion umbilical]] is tended from the bell by the bellman.<ref name="IMCA D022 2016" />

==Occupational health and safety issues==
{{see also|List of diving hazards and precautions|List of signs and symptoms of diving disorders|Human factors in diving safety}}

[[Underwater diving|Divers]] face specific physical and [[health]] risks when they go [[underwater]] with [[diving equipment]], or use high pressure [[breathing gas]].

A [[hazard]] is any agent or situation that poses a level of threat to life, health, property, or environment. Most hazards remain dormant or potential, with only a theoretical risk of harm, and when a hazard becomes active, and produces undesirable consequences, it is called an incident and may culminate in an emergency or accident.<ref name="CCOHS Hazard" /> Hazard and vulnerability interact with likelihood of occurrence to create risk, which can be the probability of a specific undesirable consequence of a specific hazard, or the combined probability of undesirable consequences of all the hazards of a specific activity.<ref name="CCOHS Risk" /> A hazard that is understood and acknowledged may present a lower risk if appropriate precautions are taken, and the consequences may be less severe if mitigation procedures are planned and in place.<ref name="Hazard and Risk" />

The presence of a combination of several hazards simultaneously is common in diving, and the effect is generally increased risk to the diver, particularly where the occurrence of an incident due to one hazard triggers other hazards with a resulting cascade of incidents. Many diving fatalities are the result of a cascade of incidents overwhelming the diver, who should be able to manage any single reasonably foreseeable incident.<ref name="Lock 2011" /> The use of surface supplied breathing gas reduces one of the most significant hazards in diving, that of loss of breathing gas supply, and mitigates that risk by the use of a suitable emergency gas supply, usually in the form of a scuba bailout set, which is intended to provide the diver with sufficient breathing gas to reach a place of relative safety with more breathing gas available.<ref name="IMCACoP" /><ref name="CoP Inshore" />

The risk of the diver getting lost or being unable to call for assistance is also drastically reduced in comparison with most scuba, as the diver is physically connected to the surface control point by the umbilical, making it relatively simple for the standby diver to get to a diver in distress, and the standard application of hard-wired voice communications allows the surface team to constantly monitor the diver's breathing sounds.<ref name="IMCA D022 2016 (5)" />

The assessed risk of a dive would generally be considered unacceptable if the diver is not expected to cope with any single reasonably foreseeable incident with a significant probability of occurrence during that dive. Precisely where the line is drawn depends on circumstances. Professional diving operations tend to be less tolerant of risk than recreational, particularly technical divers, who are less constrained by occupational health and safety legislation and codes of practice.<ref name="IMCACoP" />{{rp|35}} This is one of the factors driving the use of surface supplied equipment where reasonably practicable for professional work.

[[Diving disorders]] are [[medical conditions]] specifically arising from [[underwater diving]]. The [[Medical sign|signs]] and [[symptoms]] of these may present during a dive, on surfacing, or up to several hours after a dive. Surface supplied  divers have to breathe a gas which is at the same pressure as their surroundings ([[ambient pressure]]), which can be much greater than on the surface. The ambient pressure underwater increases by {{convert|1|atm|kPa|lk=in}} for every {{convert|10|m|ft}} of depth.<ref name="BE9" />

The principal disorders are: [[decompression illness]] (which covers [[decompression sickness]] and [[arterial gas embolism]]); [[nitrogen narcosis]]; [[high pressure nervous syndrome]]; [[oxygen toxicity]]; and [[pulmonary barotrauma]] (burst lung). Although some of these may occur in other settings, they are of particular concern during diving activities.<ref name="BE9" /> Long term diving disorders include [[dysbaric osteonecrosis]], which is associated with decompression sickness. These disorders are caused by [[breathing gas]] at the high pressures encountered at depth, and divers may breathe a gas mixture different from air to mitigate these effects. [[Nitrox]], which contains more [[oxygen]] and less [[nitrogen]], is commonly used as a breathing gas to reduce the risk of decompression sickness at depths to about {{convert|40|m|ft}}. [[Helium]] may be added to reduce the amount of nitrogen and oxygen in the gas mixture when diving deeper, to reduce the effects of narcosis and to avoid the risk of oxygen toxicity. This is complicated at depths beyond about {{convert|150|m|ft|-2}}, because a helium–oxygen mixture ([[heliox]]) then causes high pressure nervous syndrome.<ref name="BE9" /> More exotic mixtures such as [[hydreliox]], a hydrogen–helium–oxygen mixture, are used at extreme depths to counteract this.<ref name="Abraini1994" />

==Compressor diving==
<!-- target for redirect from [[Compressor diving]], [[Pa-aling]]-->
"Compressor diving" is a method of surface-supplied diving used in some tropical sea areas including the [[Philippines]] and the [[Caribbean]]. The divers swim with a [[diving mask|half mask]] covering the eyes and nose and (often home-made) fins and are supplied air from the boat by plastic hoses from an industrial low-pressure [[air compressor]] of the type commonly used to supply [[jackhammer]]s. There is no reduction valve; the diver holds the hose end in his mouth with no demand valve or [[Mouthpiece (scuba)|mouthpiece]]. Excess air spills out through the nose or lips.
If several people are compressor diving from the same boat, several line tenders are needed in the boat to stop the airlines from getting tangled and blocked by kinks.<ref name="Into the blue" />

Compressor diving is the most common method used to fish for Caribbean spiny lobster (''[[Panulirus argus]]'') in the Caribbean.<ref name="Herrera-Moreno and Betancourt 2003a" /> However, it is illegal because it contributes to overfishing, is environmentally destructive, and is harmful to the health of the fishermen.<ref name="Herrera-Moreno and Betancourt 2003b" /> When using compressors, fishermen use either gaffs or harpoons to spear lobsters immediately upon sight, killing or injuring the lobsters before they can be checked for eggs or assessed as legally sized. Compressors allow fishermen to remain in deeper waters for longer periods of time, facilitating reef damage by fishermen seeking lobsters hidden underneath corals and other living refuges. The misuse of compressors has also resulted in health problems for many fishermen, such as respiratory problems, limb paralysis, and death due to [[decompression illness]].<ref name="WWF 2006" />

This method of diving is commonly used in [[Philippines|Philippine]] waters for ''{{visible anchor|pa-aling}}'' fishing, which is fishing with big nets on coral reef areas where a surface-dragged net would snag on coral; the compressor air hoses are also used to make a curtain of bubbles to corral and herd the fish into the nets, since ''[[muro-ami]]'' fishing was stopped in the area. At least one ''pa-aling'' fishing fleet has been found and arrested in a protected fishery area. Compressor diving was shown, and so called, used for ''pa-aling'' fishing, in episode 1 (Oceans: Into the Blue) of the [[BBC television]] series ''[[Human Planet]]''. The cameramen used ordinary [[scuba gear]], but one of them had a trial-dive with the crew's compressor-diving gear.<ref name="Into the blue" />

==Training and registration==
<!-- target for redirect [[Surface-supplied diver]] -->
{{see also|Surface-supplied diving skills#Training and registration|Diver training#Professional divers}}
Almost all surface-supplied diving is done by professional divers, and consequently the training is done by schools which specialise in the training of professional divers. Registration of professional divers is generally subject to national or state legislation, though international recognition is available for some qualifications.<ref name="Diving at Work Regulations 1997" /><ref name="SA Diving Regulations 2009"/><ref name="IDSA" />

==See also==
{{div col}}
* {{annotated link|Atmospheric diving suit}}
* {{annotated link|Diver's pump}}
<!-- * {{annotated link|Diver's umbilical}} circular redirect -->
* {{annotated link|Diving bell}}
* {{annotated link|Diving chamber}}
* {{annotated link|Diving helmet}}
* {{annotated link|Freediving}}
<!-- * {{annotated link|Hookah diving}} circular redirect -->
* {{annotated link|Recreational diving}}
* {{annotated link|Saturation diving}}
* {{annotated link|Scuba diving}}
<!--* {{annotated link|Scuba replacement}} circular redirect -->
* {{annotated link|Snuba}}
* {{annotated link|Standard diving dress}}
{{div col end}}

==Notes==
{{notelist|refs=

}}

==References==
{{Reflist|refs=

<ref name="Abraini1994">{{cite journal |last1=Abraini |first1=J. H. |last2=Gardette-Chauffour |first2=M. C. |last3=Martinez |first3=E. |last4=Rostain |first4=J. C. |last5=Lemaire |first5=C. |year=1994 |title=Psychophysiological reactions in humans during an open sea dive to 500 m with a hydrogen-helium-oxygen mixture |journal=Journal of Applied Physiology |publisher=American Physiological Society |volume=76 |issue=3 |pages=1113–8 |issn=8750-7587 |pmid=8005852 |doi=10.1152/jappl.1994.76.3.1113}}</ref>

<ref name=acott>{{cite journal |last=Acott |first=C. |title=JS Haldane, JBS Haldane, L Hill, and A Siebe: A brief resume of their lives. |journal=South Pacific Underwater Medicine Society Journal |volume=29 |issue=3 |year=1999 |issn=0813-1988 |oclc=16986801 <!--|url=http://archive.rubicon-foundation.org/6016 |archive-url=https://web.archive.org/web/20110727224432/http://archive.rubicon-foundation.org/6016 |url-status=usurped |archive-date=27 July 2011 |access-date=13 July 2008--> }}</ref>

<ref name=ADA166891>{{cite report |last1=Curley |first1= M.D. |title=Human Factors Evaluation of the Superlite 17B Helmet in the Surface-Supplied, Open-Circuit Mode |publisher=US Navy Experimental Diving Unit Technical Report |volume=NEDU-11-85 |year=1986 <!--|url=http://archive.rubicon-foundation.org/3527 |archive-url=https://web.archive.org/web/20090805172653/http://archive.rubicon-foundation.org/3527 |url-status=usurped |archive-date=5 August 2009 |access-date=9 September 2008--> }}</ref>

<ref name="Ahlen 1995" >{{cite book |url=http://www.nui.no/media/24639/STF23A95006-Gas-reclaim-environmental-factors.pdf |archive-url=https://web.archive.org/web/20161020223159/http://www.nui.no/media/24639/STF23A95006-Gas-reclaim-environmental-factors.pdf |url-status=dead |archive-date=20 October 2016 |title=Gas Reclaim in Saturation Diving - Environmental factors: What do we know - what do we not know? |last=Ahlén |first=Catrine |date=31 January 1995 |isbn=82-595-9237-1 |publisher=Sintef Unimed |access-date=27 September 2016 |location=Trondheim, Norway }}</ref>

<ref name="Barsky" >{{cite book |first= Steven M. |last= Barsky |title=Diving in High-Risk Environments |year=2007 |publisher= Hammerhead Press |location=Santa Barbara, CA |isbn=978-0-9674305-7-7 }}</ref>

<ref name="Barsky and Christensen" >{{cite book |last1=Barsky |first1=Steven M. |last2=Christensen |first2=Robert W. |title=The Simple Guide to Commercial Diving |edition=illustrated |year=2004 |publisher=Hammerhead Press |isbn=9780967430546 }}</ref>

<ref name="Barsky and Neuman 2003" >{{cite book |last1=Barsky |first1=Steven |last2=Neuman |first2=Tom |title=Investigating Recreational and Commercial Diving Accidents |year=2003 |publisher=Hammerhead Press |location=Santa Barbara, California |isbn=0-9674305-3-4}}</ref>

<ref name="BE9" >{{cite book |title=Bennett and Elliott's physiology and medicine of diving |edition=5th Revised |editor1-last=Brubakk |editor1-first=Alf O. |editor2-last=Neuman |editor2-first=Tom S. |year=2003 |publisher=Saunders Ltd |location=United States |chapter=9: Pressure Effects |pages=265–418 |isbn=0-7020-2571-2 |oclc=51607923 }}</ref>

<ref name="Bevan 1966" >{{cite book |last=Bevan |first=John |title=The Infernal Diver |date=27 May 1996 |publisher=Submex Ltd |location=London |isbn=0-9508242-1-6}}</ref>

<ref name=Beyerstein >{{cite report |last=Beyerstein |first=G. |title=Commercial Diving: Surface-Mixed Gas, Sur-D-O2, Bell Bounce, Saturation. |editor1-last= Lang |editor1-first=M.A. |editor2-last=Smith |editor2-first= N.E. |work= Proceedings of Advanced Scientific Diving Workshop |location=Smithsonian Institution, Washington, DC. |year=2006 |url=http://archive.rubicon-foundation.org:80/dspace/bitstream/123456789/4661/1/ |archive-url=https://web.archive.org/web/20100921033547/http://archive.rubicon-foundation.org:80/dspace/bitstream/123456789/4661/1/ |archive-date=2010-09-21 |url-status=usurped }}</ref>

<ref name="Bluestream" >{{cite web |url=https://www.bluestreamoffshore.com/assets/files/bso-modulair-dive-spread-brochure-2021.pdf |title=Modular dive spread: Technical data sheet |website=www.bluestreamoffshore.com |access-date=19 September 2023 |archive-date=14 July 2023 |archive-url=https://web.archive.org/web/20230714190430/https://www.bluestreamoffshore.com/assets/files/bso-modulair-dive-spread-brochure-2021.pdf |url-status=live }}</ref>

<ref name="BuRec dive manual" >{{cite web |url=http://www.usbr.gov/ssle/safety/DivingManual.pdf |title=6-7 Standby (Safety) Diver Requirements |last=<!--not specified--> |date=November 2006 |work=U.S. Department of the Interior Bureau of Reclamation November 2006 Diving Safe Practices Manual Underwater Inspection Program |publisher=U.S. Department of the Interior Bureau of Reclamation |access-date=23 March 2016 |archive-date=27 December 2016 |archive-url=https://web.archive.org/web/20161227174355/https://www.usbr.gov/ssle/safety/DivingManual.pdf |url-status=live }}</ref>

<ref name="C2DTS" >{{cite book |last=<!--not specified--> |title=Class 2 Diver Training Standard |edition=Revision 5 |year=2007 |publisher=South African Department of Labour |location=Pretoria }}</ref>

<ref name="CADC 2015" >{{cite web |url=https://www.ihsa.ca/PDFs/News/CADC-Magazine-Standby-Diver.aspx |title=Diver Safety: Is the Standby Diver Actually Standing By? |last=Hayward |first=Richard |year=2015 |work=CADC Magazine |publisher=The Canadian Association of Diving Contractors |access-date=27 September 2016 |archive-date=27 September 2016 |archive-url=https://web.archive.org/web/20160927210658/https://www.ihsa.ca/PDFs/News/CADC-Magazine-Standby-Diver.aspx |url-status=live }}</ref>

<ref name="CCOHS Hazard" >{{cite web |last1=<!--not specified --> |title=Hazard and Risk - What is a hazard? |url=https://www.ccohs.ca/oshanswers/hsprograms/hazard_risk.html |website=OSH Answers Fact Sheets |publisher=Canadian Centre for Occupational Health & Safety |access-date=17 May 2017 |date=17 May 2017 |archive-date=7 May 2017 |archive-url=https://web.archive.org/web/20170507230818/http://www.ccohs.ca/oshanswers/hsprograms/hazard_risk.html |url-status=live }}</ref>

<ref name="CCOHS Risk" >{{cite web |last1=<!--not specified --> |title=Hazard and Risk - What is risk? |url=https://www.ccohs.ca/oshanswers/hsprograms/hazard_risk.html |website=OSH Answers Fact Sheets |publisher=Canadian Centre for Occupational Health & Safety |access-date=17 May 2017 |date=17 May 2017 |archive-date=7 May 2017 |archive-url=https://web.archive.org/web/20170507230818/http://www.ccohs.ca/oshanswers/hsprograms/hazard_risk.html |url-status=live }}</ref>

<ref name=CDM >{{cite book |last1=Larn |first1=Richard |last2=Whistler |first2=Rex |title=Commercial Diving Manual |edition=3rd |year=1993 |publisher=David and Charles |location=Newton Abbott, UK |isbn=0-7153-0100-4}}</ref>

<ref name="CDM 9" >{{cite book |last1=Larn |first1=Richard |last2=Whistler |first2=Rex |title=Commercial Diving Manual |edition=3rd |year=1993 |publisher=David and Charles |location=Newton Abbott |isbn=0-7153-0100-4 |pages=168–189 |chapter=Chapter 9: Surface supplied diving procedures }}</ref>

<ref name="CDM 10" >{{cite book |last1=Larn |first1=Richard |last2=Whistler |first2=Rex |title=Commercial Diving Manual |edition=3rd |year=1993 |publisher=David and Charles |location=Newton Abbott |isbn=0-7153-0100-4 |pages=190–199 |chapter=Chapter 10: Diving Emergencies }}</ref>

<ref name="CDM 11" >{{cite book |last1=Larn |first1=Richard |last2=Whistler |first2=Rex |title=Commercial Diving Manual |edition=3rd |year=1993 |publisher=David and Charles |location=Newton Abbott |isbn=0-7153-0100-4 |pages=200–203 |chapter=Chapter 11: Wet diving bells and Dynamic Positioning }}</ref>

<ref name="Clabby 2014" >{{cite web |url=http://www.maryrose.org/salvage-1836/ |title=Salvaging the Mary Rose – 1836–1843 |last=Clabby |first=Simon |year=2014 |work=The Mary Rose Museum |access-date=18 September 2016 |archive-date=18 September 2016 |archive-url=https://web.archive.org/web/20160918160031/http://www.maryrose.org/salvage-1836/ |url-status=live }}</ref>

<ref name="CoP Inshore" >{{cite book |url=http://www.labour.gov.za/DOL/downloads/documents/useful-documents/occupational-health-and-safety/inshorediving2014.pdf |title=Code Of Practice Inshore Diving |last=Diving Advisory Board |publisher=The South African Department of Labour |access-date=16 September 2016 |location=Pretoria |archive-date=9 November 2016 |archive-url=https://web.archive.org/web/20161109161003/http://www.labour.gov.za/DOL/downloads/documents/useful-documents/occupational-health-and-safety/inshorediving2014.pdf |url-status=dead }}</ref>

<ref name="Crawford 2016" >{{cite book |last=Crawford |first=J |title=Offshore Installation Practice |edition=revised |year=2016 |publisher=Butterworth-Heinemann |isbn=9781483163192 |pages=150–155 |chapter=8.5.1 Helium recovery systems }}</ref>

<ref name="Deane helmet" >{{cite web |url=http://www.divinghelmet.nl/divinghelmet/1836_Deane.html |title=1836. Charles Deane |last=Dekker |first=David L. |work=Chronology of Diving in Holland |publisher=www.divinghelmet.nl |access-date=17 September 2016 |archive-date=13 December 2016 |archive-url=https://web.archive.org/web/20161213162940/http://www.divinghelmet.nl/divinghelmet/1836_Deane.html |url-status=live }}</ref>

<ref name="Dekker Siebe" >{{cite web |url=http://www.divinghelmet.nl/divinghelmet/1839_Augustus_Siebe.html |title=1839. Augustus Siebe |last=Dekker |first=David L. |work=www.divinghelmet.nl |access-date=18 September 2016 |archive-date=10 March 2016 |archive-url=https://web.archive.org/web/20160310195045/http://www.divinghelmet.nl/divinghelmet/1839_Augustus_Siebe.html |url-status=live }}</ref>

<ref name="Denayrouze 2" >{{cite web|url=http://www.divinghelmet.nl/divinghelmet/1860_Rouquayrol_Denayrouze_2.html |title=1860. Benoit Rouquayrol – Auguste Denayrouze: Part 2 |last=Dekker |first=David L. |work=www.divinghelmet.nl |access-date=18 September 2016 |url-status=live |archive-url=https://web.archive.org/web/20160310134921/http://www.divinghelmet.nl/divinghelmet/1860_Rouquayrol_Denayrouze_2.html |archive-date=10 March 2016 }}</ref>

<ref name="DiveN2Life" >{{cite web|url=https://www.youtube.com/watch?v=d_S1fI5c0cg |title=Removing and Replacing the Full Face Mask At-Depth |date=20 January 2021 |via=YouTube |access-date=23 June 2025 |publisher=DiveN2Life Organization }}</ref>

<ref name="Diving at Work Regulations 1997" >{{cite web |url=http://www.legislation.gov.uk/uksi/1997/2776/made |title=The Diving at Work Regulations 1997 |last=<!--not specified --> |year=1977 |work=Statutory Instruments 1997 No. 2776 Health and Safety |publisher=Her Majesty's Stationery Office (HMSO) |location=Kew, Richmond, Surrey |access-date=6 November 2016 |archive-date=31 October 2019 |archive-url=https://web.archive.org/web/20191031191337/http://www.legislation.gov.uk/uksi/1997/2776/made |url-status=live }}</ref>

<ref name="Divingheritage Deane" >{{cite web |url=http://www.divingheritage.com/deanekern.htm |title=Charles and John Deane. The first diving helmet. |work=Diving Heritage |access-date=17 September 2016 |archive-date=1 July 2014 |archive-url=https://web.archive.org/web/20140701081119/http://www.divingheritage.com/deanekern.htm |url-status=live }}</ref>

<ref name="Draeger 2016" >{{cite web |url=http://www.draeger.com/sites/en_me/Pages/Chemical-Industry/Draeger-Panorama-Nova-Dive.aspx |title=Dräger Panorama Nova Dive |last=<!--not specified --> |year=2016 |work=Diving equipment and systems |publisher=Drägerwerk AG & Co. KGaA |access-date=27 September 2016 |archive-date=20 January 2016 |archive-url=https://web.archive.org/web/20160120070541/http://www.draeger.com/sites/en_me/Pages/Chemical-Industry/Draeger-Panorama-Nova-Dive.aspx |url-status=live }}</ref>

<ref name="Draegerwerk" >{{cite web|url=http://www.divinghelmet.nl/divinghelmet/1899_Draegerwerk.html |title=1889. Draegerwerk Lübeck |last=Dekker |first=David L. |work=Chronology of Diving in Holland |publisher=www.divinghelmet.nl |access-date=17 September 2016 |url-status=live |archive-url=https://web.archive.org/web/20160920034736/http://www.divinghelmet.nl/divinghelmet/1899_Draegerwerk.html |archive-date=20 September 2016 }}</ref>

<ref name="DSM 1st ed" >{{cite book |last=<!--not specified--> |editor-first=Paul |editor-last=Williams |title=The Diving Supervisor's Manual |url=http://www.imca-int.com/diving |edition=IMCA D 022 May 2000, incorporating the May 2002 erratum |year=2002 |publisher=International Marine Contractors' Association |location=London, UK |isbn=1-903513-00-6 |access-date=4 October 2013 |archive-date=12 August 2001 |archive-url=https://web.archive.org/web/20010812220108/http://www.imca-int.com/diving/ |url-status=live }}</ref>

<ref name="FAO Hookah" >{{cite book |url=https://www.fao.org/documents/card/en?details=cc3789en |title=A practical guide on safe hookah diving |date=2023 |first1=Giampaolo |last1=Buonfiglio |first2=Alessandro |last2=Lovatelli |publisher=Food and Agriculture Organization of the United Nations |location=Rome |isbn=978-92-5-137476-4 |access-date=2023-09-20 |archive-date=2023-09-29 |archive-url=https://web.archive.org/web/20230929202852/https://www.fao.org/documents/card/en?details=cc3789en |url-status=live }}</ref>

<ref name="Gasmizer" >{{cite web |url=https://www.jfdglobal.com/products/gas-and-fluid-systems/diver-gas-reclaim/electric-gasmizer/ |title=Electric Gasmizer |last=<!--not specified --> |year=2016 |work=Divex Products |publisher=James Fisher and Sons plc |access-date=27 September 2016 |location=Scotland |archive-date=23 August 2017 |archive-url=https://web.archive.org/web/20170823165519/https://www.jfdglobal.com/products/gas-and-fluid-systems/diver-gas-reclaim/electric-gasmizer/ |url-status=live }}</ref>

<ref name=gernhardt >{{cite conference |last=Gernhardt |first=M.L. |title=Biomedical and Operational Considerations for Surface-Supplied Mixed-Gas Diving to 300&nbsp;fsw. |editor1-last=Lang |editor1-first=M.A. |editor2-last=Smith |editor2-first=N.E. |work=Proceedings of Advanced Scientific Diving Workshop |publisher= Smithsonian Institution |location=Washington, DC |year=2006 <!--|url=http://archive.rubicon-foundation.org/4655 |archive-url=https://web.archive.org/web/20090805172658/http://archive.rubicon-foundation.org/4655 |url-status=usurped |archive-date=5 August 2009 |access-date=12 September 2008--> }}</ref>

<ref name="Hardwire" >{{cite web |url=http://www.oceantechnologysystems.com/hardwire-further-explained/ |title=Hardwire – Further Explained |last=<!--not specified--> |year=2015 |publisher=Ocean Technology Systems |access-date=27 September 2016 |archive-date=27 September 2016 |archive-url=https://web.archive.org/web/20160927213711/http://www.oceantechnologysystems.com/hardwire-further-explained/ |url-status=live }}</ref>

<ref name="Hazard and Risk" >{{cite web |last1=<!--not specified--> |title=Hazard and Risk |url=http://www.hsa.ie/eng/Topics/Hazards/ |publisher=Health & Safety Authority (Ireland) |access-date=17 May 2017 |archive-date=18 May 2017 |archive-url=https://web.archive.org/web/20170518205103/http://hsa.ie/eng/Topics/Hazards/ |url-status=live }}</ref>

<ref name="Herrera-Moreno and Betancourt 2003a" >{{cite report |last1=Herrera-Moreno |first1=A. |last2=Betancourt |first2=L. |year=2003 |title=Datos de la Pesca de la Langosta ''Panulirus argus'' en la Republica Dominicana |editor=Buho |work=Investigaciones ecologico pesqueras de la langosta Panulirus argus en la Plataforma Dominicana |pages=24–44 |location=Santo Domingo, Republica Dominicana |publisher=Servicio de Publicaciones, Universidad de Cadiz |language=es }}</ref>

<ref name="Herrera-Moreno and Betancourt 2003b" >{{cite report |last1=Herrera-Moreno |first1=A. |last2=Betancourt |first2=L. |year=2003 |title=Pautas para el Ordenamiento de la Pesca de la Langosta Panulirus argus en la Republica Dominicana |editor=Buho |work=Investigaciones Ecologico Pesqueras de la Langosta Panulirus argus en la Plataforma Dominicana |pages=94–117 |location=Santo Domingo, Republica Dominicana |publisher=Servicio de Publicaciones, Universidad de Cadiz. |language=es }}</ref>

<ref name="Historical diver 1995" >{{cite web |url=http://aquaticcommons.org/14992/1/Historical_Diver_5_1995.pdf |title=The world's first diving manual |last=<!--not specified --> |year=1995 |work=Historical Diver |publisher=Historical diving society USA |pages=9–12 |access-date=17 September 2016 |archive-date=17 September 2016 |archive-url=https://web.archive.org/web/20160917164132/http://aquaticcommons.org/14992/1/Historical_Diver_5_1995.pdf |url-status=live }}</ref>

<ref name="IDSA" >{{cite web |url=http://www.idsaworldwide.org/docs/diverts0909.pdf |title=International Diver Training Certification: Diver Training Standards, Revision 4 |last=<!--not specified--> |date=29 October 2009 |work=Diver Training Standards |publisher=International Diving Schools Association |access-date=6 November 2016 |location=Malestroit, Brittany |url-status=dead |archive-url=https://web.archive.org/web/20160303215439/http://www.idsaworldwide.org/docs/diverts0909.pdf |archive-date=3 March 2016 }}</ref>

<ref name=IMCACoP >{{cite book |author=IMCA |title=IMCA International Code of Practice for Offshore Diving |date=October 2007 |url=http://www.imca-int.com/documents/divisions/diving/docs/IMCAD014.pdf |access-date=2011-07-24 |url-status=dead |archive-url=https://web.archive.org/web/20110815121128/http://www.imca-int.com/documents/divisions/diving/docs/IMCAD014.pdf |archive-date=15 August 2011 }}</ref>

<ref name="IMCA D014" >{{cite web |url=http://www.imca-int.com/(F(j70H1MPWJUEd5ZLLliou69laSOu_Vf5cJb-X6cXE01yT_UtIzy96iOzCsRu65U9YkeW7Lq6Gm8g1Cvt-ipseHW_DAaaSDS-AQ5AYIXIAFOzW2yB0GO8frgISnDAWTTEFN6DqnwilT79LcpK_jFtKYGrhn97gPAZ0XT4TbqycNpY1))/media/70842/imcad014.pdf |title=IMCA International Code of Practice for Offshore Diving |last=<!--not specified--> |date=February 2014 |work=IMCA D 014 Rev. 2 |publisher=International Marine Contractor's Association |location=London |access-date=22 July 2016 }}</ref>

<ref name="IMCAD022" >{{cite book |last=<!--not specified--> |editor=Paul Williams |title=The Diving Supervisor's Manual |url=http://www.imca-int.com/diving |edition=IMCA D 022 May 2000, incorporating the May 2002 erratum |year=2002 |publisher=International Marine Contractors' Association |location=London |isbn=1-903513-00-6 |access-date=4 October 2013 |archive-date=12 August 2001 |archive-url=https://web.archive.org/web/20010812220108/http://www.imca-int.com/diving/ |url-status=live }}</ref>

<ref name="IMCA D022 2016" >{{cite book |last=<!--not specified-->|title=Guidance for diving supervisors IMCA D 022 |edition=Revision 1 |date=August 2016 |publisher=International Marine Contractors Association |location=London, UK |pages=10{{hyphen}}6 |chapter=10 - General diving procedures. Section 10.3 - Divers umbilicals }}</ref>

<ref name="IMCA D022 2016 (5)" >{{cite book |last=<!--not specified--> |title=Guidance for diving supervisors IMCA D 022 |edition=Revision 1 |date=August 2016 |publisher=International Marine Contractors Association |location=London, UK |pages=5{{hyphen}}3 |chapter=5 - Communications }}</ref>

<ref name=IMCAD043 >{{cite book |last=<!--not specified--> |title=Marking and Colour Coding of Gas Cylinders, Quads and Banks for Diving Applications IMCA D043 |url=http://www.imca-int.com/%28F%28HgoxzyeluluOK_Nh2f6_zim-2B84gkOvCTu_AmwHNcKDtdlHYtGfqT-wmnIrcBoQE0ipE1nbMQerGIKG2VBUAyxvfXjbagbYuWkWR7ajBSMlpv65vptXhWARBOd7Y7opa-v9UX7emzJTcA9qeePkvrwLsv_G1ymrPxbJKe_w__w1%29%29/media/71123/imcad043.pdf |access-date=1 February 2016 |year=2007 |publisher=International Marine Contractors Association |location=London, UK }}{{dead link |date=December 2017 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>

<ref name="IMCA SF15/09" >{{cite web|url=https://www.imca-int.com/resources/safety/safety-flashes/1509-trapped-diver-umbilical-incident-resulting-in-diver-fatality/ |title=Trapped diver umbilical incident resulting in diver fatality |work=IMCA SF 15/09 |publisher=IMCA |location=London, UK |date=23 October 2009 }}</ref>

<ref name="Into the blue" >{{cite web |url=https://www.bbc.co.uk/programmes/b00rrd81 |title=Oceans: Into the blue |last=<!-- not specified--> |date=13 January 2011 |work=Human Planet: Episode 1 |publisher=BBC |access-date=27 September 2016 |archive-date=31 July 2016 |archive-url=https://web.archive.org/web/20160731130722/http://www.bbc.co.uk/programmes/b00rrd81 |url-status=live }}</ref>

<ref name="inshore" >{{cite book |last=<!--not specified--> |title=Code of Practice: Inshore Diving |edition=4.0 |publisher=The South African Department of Labour }}</ref>

<ref name="Jones 2008" >{{cite web |last1=Jones |first1=Gary |title=The Jump Jacket Mk4 Instruction Manual |url=http://www.apvalves.com/uk/graphics/manuals/JJ%20Mk4%20Manual%20revision%20June08.pdf |publisher=AP Valves |date=2008 |access-date=2011-10-27 |archive-date=2012-04-25 |archive-url=https://web.archive.org/web/20120425112719/http://www.apvalves.com/uk/graphics/manuals/JJ%20Mk4%20Manual%20revision%20June08.pdf |url-status=live }}</ref>

<ref name="KM77" >{{cite web |last1=<!--not specified--> |title=Kirby Morgan 77 Diver's Helmet Operations and Maintenance Manual |url=http://kmdsi.com/PDF/Manuals/77_Manual/KM77_Complete.pdf |website=KMDSI Part #100-085 |publisher=Kirby Morgan Dive Systems, Inc |location=Santa Maria, CA. }}{{Dead link|date=January 2024 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>

<ref name="KM OPRV" >{{cite web |last1=<!--not specified--> |title=Overpressure Relief Valve - Document # 140130019 |url=http://www.kirbymorgan.com/sites/default/files/pdf/modular_manuals/overpressure_relief_valve.pdf |publisher=Kirby Morgan Dive Systems, Inc |access-date=17 May 2017 |date=2014 }}{{Dead link|date=January 2024 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>

<ref name="Lock 2011" >{{cite book |last=Lock |first=Gareth |title=Human factors within sport diving incidents and accidents: An Application of the Human Factors Analysis and Classification System (HFACS) |url=https://cognitasresearch.wordpress.com/ |year=2011 |publisher=Cognitas Incident Research & Management |access-date=2017-05-17 |archive-date=2021-03-08 |archive-url=https://web.archive.org/web/20210308063256/https://cognitasresearch.wordpress.com/ |url-status=live }}</ref>

<ref name="M-48" >{{cite web |url=http://www.kirbymorgan.com/products/full-face-masks/m-48-supermask |title=M-48 SuperMask |last=<!--not specified --> |year=2016 |work=Products: Full-face masks |publisher=Kirby Morgan Dive Systems, Inc |access-date=27 September 2016 |archive-date=4 December 2016 |archive-url=https://web.archive.org/web/20161204145547/http://www.kirbymorgan.com/products/full-face-masks/m-48-supermask |url-status=live }}</ref>

<ref name="Neptune II" >{{cite web |url=http://diving.oceanreefgroup.com/product/neptune-ii/ |title=Neptune II |last=<!--not specified --> |work=Products |publisher=Ocean Reef Inc. |access-date=27 September 2016 |location=San Marcos, California |archive-date=27 September 2016 |archive-url=https://web.archive.org/web/20160927210342/http://diving.oceanreefgroup.com/product/neptune-ii/ |url-status=live }}</ref>

<ref name="NOAA 4th Ed" >{{cite book |title=NOAA Diving Manual, Diving for Science and Technology |author=NOAA Diving Program (U.S.) |edition=4th |editor-first=James T. |editor-last=Joiner |date=28 Feb 2001 |publisher=National Oceanic and Atmospheric Administration, Office of Oceanic and Atmospheric Research, National Undersea Research Program |location=Silver Spring, Maryland |isbn=978-0-941332-70-5 |url=https://archive.org/details/noaadivingmanual00noaa |ref={{sfnRef|NOAA Diving Manual|2001}} |url-access=registration }}</ref>

<ref name="Offshore" >{{cite web |url=https://www.offshore-mag.com/business-briefs/equipment-engineering/article/16759121/subsea-technology-atmospheric-diving-suits-bridge-gap-between-saturation-diving-and-rov-units |title=Subsea Technology: Atmospheric diving suits bridge gap between saturation diving and ROV units |first1=Mike |last1=Thornton |first2=Robert E. |last2=Randall |first3=E. Kurt |last3=Albaugh |date=1 January 2001 |access-date=20 September 2023 }}</ref>

<ref name="OSO 2011" >{{cite web |url=http://www.oilpubs.com/oso/article.asp?v1=10926 |title=IMCA publishes info note on divers' gas supply |last=<!--not specified --> |date=29 June 2011 |work=Offshore Shipping Online (website) |publisher=Clarkson Research |access-date=23 March 2016 |archive-date=4 April 2016 |archive-url=https://web.archive.org/web/20160404232245/http://www.oilpubs.com/oso/article.asp?v1=10926 |url-status=live }}</ref>

<ref name="PDC manual" >{{cite book |title=New Commercial Air Diving Manual |first=Grant |last=Jameson |publisher=Professional Diving Centre |location=Durban, South Africa }}</ref>

<ref name="SA Diving Regulations 2009" >{{cite web |title=Diving Regulations 2009 |work=Occupational Health and Safety Act 85 of 1993 – Regulations and Notices – Government Notice R41 |url=http://www.saflii.org/za/legis/consol_reg/ohasa85o1993rangnr41716/ |publisher=Government Printer |location=Pretoria |via=Southern African Legal Information Institute |access-date=3 November 2016 |url-status=dead |archive-url=https://web.archive.org/web/20161104080007/http://www.saflii.org/za/legis/consol_reg/ohasa85o1993rangnr41716/ |archive-date=4 November 2016 }}</ref>

<ref name="scubadoc hookah" >{{cite web |url=https://www.scubadoctor.com.au/intro-to-hookah-diving.htm |website=The Scuba Doctor |title=Hookah Diving |access-date=9 January 2024 |archive-date=13 November 2023 |archive-url=https://web.archive.org/web/20231113200231/https://www.scubadoctor.com.au/intro-to-hookah-diving.htm |url-status=live }}</ref>

<ref name="seattle1995" >{{cite news |url=https://archive.seattletimes.com/archive/19950122/2100660/snuba-diving-offers-a-chance-to-experience-rapture-of-the-shallows |title=Snuba Diving Offers A Chance To Experience Rapture Of The Shallows |last=Jackson |first=Kristin |date=1995-01-22 |work=Seattle Times |publisher=Seattle Times Company |access-date=2016-09-27 |archive-date=2012-09-22 |archive-url=https://web.archive.org/web/20120922085608/http://community.seattletimes.nwsource.com/archive/?date=19950122&slug=2100660 |url-status=live }}</ref>

<ref name="Scuba Ed's" >{{cite web |url=http://scubaeds.com/10.html |title=Scuba Ed's - History of scuba diving |website=scubaeds.com |date=27 November 2018 |access-date=5 January 2014 |archive-date=27 October 2013 |archive-url=https://web.archive.org/web/20131027105226/http://scubaeds.com/10.html |url-status=usurped }}</ref>

<ref name="SPAS" >{{cite web |url=https://www.youtube.com/watch?v=eMQydsVOsLE&ab_channel=SubseaPartnerAS |title=SPAS TUP - Transfer under pressure |website=www.youtube.com |date=5 November 2020 |access-date=9 March 2024 |archive-date=9 March 2024 |archive-url=https://web.archive.org/web/20240309125757/https://www.youtube.com/watch?v=eMQydsVOsLE&ab_channel=SubseaPartnerAS |url-status=live }}</ref>

<ref name="SSBA Standby" >{{cite web |url=https://www.youtube.com/watch?v=NlJ4mo9uX5s |website=www.youtube.com |author=ADAS |title=SSBA Standby Diver Safety |publisher=Safework NSW |date=12 January 2016 |accessdate=15 February 2022 |archive-date=15 February 2022 |archive-url=https://web.archive.org/web/20220215094924/https://www.youtube.com/watch?v=NlJ4mo9uX5s |url-status=live }}</ref>

<ref name="Standby diver" >{{cite web |url=https://training.gov.au/Training/Details/PUADEFDV003B |title=Act as a standby diver (Release 1) |last=<!--not specified--> |date=9 February 2011 |work=Unit of competency details PUADEFDV003B |publisher=training.gov.au |access-date=27 September 2016 |archive-date=11 October 2016 |archive-url=https://web.archive.org/web/20161011094711/https://training.gov.au/Training/Details/PUADEFDV003B |url-status=live }}</ref>

<ref name="Supsalv 2019">{{cite book|title=Guidance for Diving in Contaminated Waters, Rev 2. SS521-AJ-PRO-010 |date=4 October 2019 |url=https://www.navsea.navy.mil/Portals/103/Documents/SUPSALV/Diving/Contaminated%20Water%20Dive%20Man%20Rev2.pdf?ver=e2bohX39ZcM8419yHLAX9g%3d%3d |publisher=Naval Sea Systems Command:Supervisor of Salvage and Diving |location=Washington, DC }}</ref>

<ref name="Tennessee aquarium" >{{cite web |url=https://tnaqua.org/app/uploads/2020/06/Surface-Supplied_Manual.pdf |title=Surface-supplied Diver Training Manual |publisher=Diving Control Board, Tennessee Aquarium |location=Chattanooga, TN |edition=1st |date=2007 }}</ref>

<ref name="TUP" >{{cite web |url=https://bgsmission.gr/wp-content/uploads/2018/07/Transfer-Under-Pressure-TUP-VA-min.pdf |title=Transfer Under Pressure (TUP) dive system |website=bgsmission.gr |access-date=9 March 2024 |archive-date=24 March 2023 |archive-url=https://web.archive.org/web/20230324144759/https://bgsmission.gr/wp-content/uploads/2018/07/Transfer-Under-Pressure-TUP-VA-min.pdf |url-status=live }}</ref>

<ref name="USN 1943" >{{YouTube | _jxeUl2KQaU | "Deep Sea Diving Suit: The Diving Dress 1943 US Navy Training Film" }}</ref>

<ref name="USN 1963" >{{YouTube | 0Iy0F9MI8p8 | "Deep Sea Diving: Assembling the Deep Sea Outfit – 1963 – US Navy Training" }}</ref>

<ref name=USNcontam >{{cite book |author=US Naval Sea Systems Command |title=US Navy Contaminated Water Manual: Guidance for diving in contaminated waters. |volume=SS521-AJ-PRO-010 |year=2004 <!--|url=http://archive.rubicon-foundation.org/6158 |archive-url=https://web.archive.org/web/20090221011749/http://archive.rubicon-foundation.org/6158 |url-status=usurped |archive-date=February 21, 2009 |access-date=2008-09-09--> }}</ref>

<ref name="US Navy Diving Manual Revision 6 Ch9" >{{cite book |title=US Navy Diving Manual, 6th revision |year=2008 |publisher=US Naval Sea Systems Command |location=United States |url=http://www.supsalv.org/00c3_publications.asp?destPage=00c3&pageID=3.9 |access-date=2008-06-15 |author=US Navy |archive-date=2008-05-02 |archive-url=https://web.archive.org/web/20080502023541/http://www.supsalv.org/00c3_publications.asp?destPage=00c3&pageId=3.9 |url-status=dead }}</ref>

<!-- <ref name="USN training" >{{YouTube| 1cwYe9gga9k | "U.S. Navy Standard Deep Sea Diving Outfit training film 43424 NA" }}</ref> -->

<ref name="USNDM R1" >{{cite book|url=https://apps.dtic.mil/dtic/tr/fulltext/u2/a112710.pdf |archive-url=https://web.archive.org/web/20190702185411/https://apps.dtic.mil/dtic/tr/fulltext/u2/a112710.pdf |url-status=live |archive-date=July 2, 2019 |title=US Navy Diving Manual Revision 1 Navsea-0994-LP001-9020 |date=July 1981 |volume=2 |chapter=12 |publisher=Navy Department |location=Washington DC}}</ref>

<ref name="UWC 2014" >{{cite web |last1=<!--not specified--> |title=Band Mask or Hard Hat – An Explanation of Commercial Diver Helmets |url=http://blog.theunderwatercentre.com/2014/11/band-mask-or-hard-hat-an-explanation-of-commercial-diver-helmets/ |publisher=The Underwater Centre |access-date=17 May 2017 |date=15 November 2014 |archive-date=17 May 2017 |archive-url=https://web.archive.org/web/20170517175227/http://blog.theunderwatercentre.com/2014/11/band-mask-or-hard-hat-an-explanation-of-commercial-diver-helmets/ |url-status=live }}</ref>

<ref name=Ward2006 >{{cite conference |last1=Ward |first1=M.F. |title=A Comparison of Surface-Supplied Diving Systems for Scientific Divers |editor1-last=Lang |editor1-first=M.A. |editor2-last=Smith |editor2-first=N.E. |work=Proceedings of Advanced Scientific Diving Workshop |date=23–24 February 2006 |publisher=Smithsonian Institution |location=Washington, DC <!--|url=http://archive.rubicon-foundation.org/4663 |archive-url=https://archive.today/20130415175429/http://archive.rubicon-foundation.org/4663 |url-status=usurped |archive-date=April 15, 2013 |access-date=2011-09-13--> }}</ref>

<ref name="Wilkins 2006" >{{cite conference |last=Wilkins |first=J.R. |title=US Navy Diving Program: Diving to 300 Ft Depths Using Surface-Supplied and Saturation Fly-Away Diving Systems |editor1-last=Lang |editor1-first=M.A. |editor2-last=Smith |editor2-first=N.E. |work=Proceedings of Advanced Scientific Diving Workshop |date=23–24 February 2006 |publisher=Smithsonian Institution |location=Washington, DC <!--|url=http://archive.rubicon-foundation.org/4660 |archive-url=https://web.archive.org/web/20090221011725/http://archive.rubicon-foundation.org/4660 |url-status=usurped |archive-date=February 21, 2009 |access-date=12 September 2008--> }}</ref>

<ref name="WWF 2006" >{{cite report |last=WWF |year=2006 |title=Como Lograr Mayores Ingresos Pescando de Manera Sustentable |work=Manual Practicas Pesqueras de Langosta en el Arrecife Mesoamericano. |publisher=WWF-Mexico/Centroamerica |pages=97 |language=es}}</ref>

}}

==External links==
'''Hookah''':
* [http://www.keeneeng.com/pamphlets/introHooka.html Introduction to hooka diving]
'''Compressor diving'''
* [http://humanplanet.com/timothyallen/2011/01/pa-aling-fishing/ Photographs of Pa-aling compressor diving in the Philippines]
* [http://www.gmanews.tv/story/210487/bbc-docu-features-dangerous-fishing-method-in-phl BBC documentary features ‘dangerous’ fishing method in the Philippines]
* [https://web.archive.org/web/20130330084351/http://www.bbc.co.uk/programmes/p00d53z5 BBC One - Human Planet, Oceans - Into the blue. Pa-aling divers] (with link to video)

{{Underwater diving|divequ}}
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{{DEFAULTSORT:Surface-Supplied Diving}}
[[Category:Surface supplied diving procedures]]
[[Category:Underwater diving modes]]
[[Category:Underwater diving safety]]

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