Scuba set 1

Scuba setA scuba set is an independent breathing set that provides a scuba diver with the breathing gas necessary to breatheunderwater during scuba diving. It is much used for sport diving and some sorts of work diving.The word SCUBA was originally an acronym for Self-Contained Underwater Breathing Apparatus. These initialsoriginated in 1939 in the United States Navy to refer to their military diver's rebreather sets. As with radar, theacronym has become so familiar that it is often not capitalized and is treated as an ordinary noun; for example, it hasbeen taken into the Welsh language as "sgwba".

A scuba diver in usual sport diving gear

Types

Modern scuba sets are of two types:• open-circuit (In Europe, it is often called an "aqualung", see

Aqua-Lung, first invented by Jacques Yves Cousteau and ÉmileGagnan). Here the diver breathes in from the equipment and all theexhaled gas goes to waste in the surrounding water. This type ofequipment is relatively simple, making it cheaper and more reliable.The two-hose design originally used was the one designed byCousteau and Gagnan. The single-hose design generally used todaywas invented in Australia by Ted Eldred.

• closed-circuit/semi-closed circuit (also referred to as a rebreather). Here the diver breathes in from the set, andbreathes back into the set, where the exhaled gas is processed to make it fit to breathe again. These existed beforethe open-circuit sets and are still used, but less so than open-circuit sets.

Both types of scuba provide a means of supplying air or other breathing gas, nearly always from a high pressurediving cylinder, and a harness to strap it to the diver's body. Most open-circuit scuba and some rebreathers have ademand regulator to control the supply of breathing gas. Some "semi-closed" rebreathers only have a constant-flowregulator, or occasionally a set of constant-flow regulators of various outputs.Some divers use the word "scuba" to mean open-circuit sets only.

Open circuit

A diving cylinder with its various components

The duration of open-circuit dives is shorter than a rebreather dive,in proportion to the weight and bulk of the set. Open-circuit can beless economic than a rebreather when used with expensive gasmixes such as heliox and trimix. Most divers breathe normal airi.e., 21% oxygen and 79% nitrogen. The cylinder is nearly alwaysworn on the back. "Twin sets" with two backpack cylinders weremuch more common in the 1960s than now; although twincylinders ("doubles") are commonly used by technical divers forincreased dive duration and redundancy. At one time a firm calledSubmarine Products sold a sport air scuba with three backpack cylinders. Cave divers sometimes have cylindersslung at their sides instead, allowing them to swim through narrower spaces.

See diving cylinder for more information about the cylinders and how they are arranged.

Newspapers and television news often describe open circuit scuba wrongly as "oxygen" equipment, probably by false analogy to airplane pilots' oxygen cylinders. Until Enriched Air Nitrox was widely accepted in the late 1990s,

Scuba set 2

almost all sport scuba used simple compressed air. This allowed the scuba industry in the U.S. to avoid regulation bythe U.S. Food and Drug Administration (FDA), which defines non-air gas mixtures intended to prevent or treatdiseases as "drugs". Exotic gas mixtures presently used in scuba are intended to prevent decompression illness indiving, but officially, the FDA appears to continue to believe that scuba divers all use compressed air.At higher than normal partial pressures, oxygen becomes toxic, so scuba divers limit their exposure to less than1.6 bar.[1] Open-circuit scuba sets may supply various breathing gases, but rarely pure oxygen, except duringdecompression stops in technical diving.Some divers use Enriched Air Nitrox, which has a higher percentage of oxygen, usually 32% or 36% (EAN32 andEAN36, respectively). This lets them stay underwater longer, because less nitrogen is absorbed into the body'stissues. The drawback to the higher oxygen content is that the maximum diving depth is decreased in order to avoidoxygen toxicity. The common nitrox blending method by partial pressure requires that the cylinder is in "oxygenservice", which is a cylinder that has had any non-oxygen-compatible grease or rubber removed, by cleaning andreplacing parts.

Constant flowConstant flow scuba sets do not have a demand regulator; the breathing gas flows at a constant rate, unless the diverswitches it on and off by hand. They run out of air quicker than aqualungs. There were attempts at designing andusing these before 1939, for diving and for industrial use. Examples were "Ohgushi's Peerless Respirator", andCommandant le Prieur's breathing sets; see Timeline of diving technology.

With a demand regulatorThis type of set consists of one or more diving cylinders containing breathing gas at high pressure, typically 200–300bars (3000–4000 psi), connected to a diving regulator. The regulator supplies the diver with as much of the gas asneeded, at a pressure suitable for breathing at the depth of the diver.Colloquially this type of breathing set is sometimes (depending on the country of the English speaker) often calledan aqualung. The word Aqua-Lung, which first appeared in the Cousteau-Gagnan patent, is a trademark, currentlyowned by U.S. Divers.

Twin-hose

Classic twin-hose Cousteau-type aqualung

This is the first type of diving demand valve to come into general use,and the one that can be seen in classic 1960s television scubaadventures, such as Sea Hunt. They often had two cylinders.

In this type of set, the two (or occasionally one or three) stages of theregulator are in a large circular valve assembly mounted on top of thecylinder pack. This type has two wide bellows-like breathing tubes likethose on many modern rebreathers, one for intake and one forexhalation. The return tube was not for rebreathing, but because the airexhaust needed to be as near as possible to the regulator's second stagediaphragm, to avoid pressure differences, which would cause afree-flow of gas, or extra resistance to breathing, according to thediver's orientation in the water — head-up, head-down, level. Inmodern single-hose sets this problem is avoided by moving thesecond-stage regulator to the diver's mouthpiece. The twin-hose sets came with a mouthpiece as standard, but afull-face diving mask was an option. Another optional extra was a mouthpiece that also had a snorkel attached and avalve to switch between aqualung and snorkel.

Scuba set 3

Note the correct layout of this type, in the image to the right. There have been many incorrect depictions in comics oftwo-cylinder twin-hose aqualungs, showing one wide breathing tube coming directly out of each cylinder top with noregulator.

Single-hose

A single-hose regulator with 2nd stage, gauges,BC attachment, and dry suit hose. See further

detail in photo description.

Most modern open-circuit scuba sets have a diving regulator consistingof a first-stage pressure-reducing valve fastened over the divingcylinder's output valve. This valve cuts the pressure from the cylinder,which may be up to 300 bars (4400 psi), to a constant lower pressure,often about 10 bar above the ambient pressure, which is used in the"low pressure" part of the system. A relatively thin low-pressure hoselinks this with the second-stage regulator, or "demand valve," which islocated in the mouthpiece. Exhalation occurs out of a one-waydiaphragm in the chamber of the demand valve, directly into the waterquite close to the diver's mouth. This configuration type is called"single hose". The first make of this sort of scuba was the Porpoise,which was made in Melbourne, Australia by Ted Eldred. Some earlysingle hose scuba sets used full-face masks instead of a mouthpiece,such as those made by Desco [2] and Scott Aviation [3] (who continueto make breathing units of this configuration for use by firefighters).

The first Porpoise scuba set design was a rebreather, but when ademonstration resulted in a diver passing out, Eldred began to developthe single-hose open-circuit scuba system. Its regulator's first stage andsecond stage had to be separated to avoid the Cousteau-Gagnan patent, which protected the double-hose scuba. In theprocess, Eldred also improved performance.

Scuba set 4

The safety second regulator on an octopus, and integrated into the BC

SCUBA backpack with backplate buoyancy compensator 1)DV/Regulator first stage 2) Tank shut-off valve 3) Shoulder straps 4)

Buoyancy compensator bladder 5) Buoyancy compensator bladderrelief and bottom manual dump valve 6) DV/Regulator second stages(with “octopus”) 7) Console (pressure gauge, depth gauge & compass)

8) Dry-suit inflator hose 9) “Lacasse” backplate 10) Buoyancycompensator inflator hose and inflator button 11) Buoyancycompensator mouthpiece and top manual dump valve 12)

Under-crotch strap 13) Abdominal straps

Most modern scuba sets have a spare second-stagedemand valve on a separate hose, a configurationcalled an "octopus", because it often has two or morehoses for other purposes coming out of the primaryregulator on the cylinder top. This separatesecond-stage regulator and hose, or "alternate airsource", "safe secondary" or "safe-second" for short, istypically yellow in color, signaling that it is anemergency or backup device. It is often worn securedinto a clip on the buoyancy compensator (BC) or aspecial friction plug on a diver's chest, easily availableto be grabbed by, or offered to, a second diver short ofair. In so doing, this second mouthpiece eliminates theneed for two divers who need to share a cylinder to"buddy-breathe," by trading off the same mouthpiece.Diving instructors still continue to teachbuddy-breathing as a now obsolete but still usefultechnique to know; then they show the new methodthat has superseded it, since availability of twosecondary regulators per diver is now assumed in allmodern scuba sets.

The original octopus idea was conceived bycave-diving pioneer Sheck Exley as a way forsingle-file-swimming cave divers to share air in anarrow tunnel, but has now become the standard inrecreational diving. Modern "octopus" typeprimary-stage regulators also typically featurehigh-pressure ports for use by dive-computer pressuresensors, and additional ports for additionallow-pressure hoses for inflation of dry suits and BCdevices.

Increasingly, in the 21st century, the second "safety" second-stage regulator/mouthpiece has been combined with theinflator and exhaust assembly of the integrated weight BC device. This combination eliminates the need for aseparate low pressure hose for the BC (though the low pressure hose for the combined use must be larger thandedicated BC inflation hoses, because demand on it will be higher if it is used for breathing). In this configuration,the safety spare regulator is now integral to the BC, rather than deriving as a separate hose/regulator from theoctopus.No matter which configuration of safety secondary regulator is used, many diving schools now suggest that a diver routinely offer another diver in trouble their "primary" mouthpiece, i.e., the one in their mouth, before going to their own safe-secondary regulator. The idea behind this technique is that the primary mouthpiece is certain to be working, and the diver not in trouble has much more time to sort things out with his/her own equipment after temporarily losing ability to breathe (in a great many instances, panicked out-of-air divers have grabbed the primary regulators out of the mouths of other divers, so changing breathing regulators suddenly in an out-of-air emergency becomes necessary for the rescue diver, in any case). With integrated regulator/BC designs, the safe-secondary

Scuba set 5

regulator is at the end of an even shorter hose (the BC mouthpiece/exhaust) than is the case with the traditionaloctopus safe-secondary, so deliberate use of the primary regulator and hose to help another diver becomes even morenatural, and almost necessary, with the BC-integrated-regulator configuration.

Cryogenic

There have been designs for a cryogenic open-circuit scuba which has liquid-air tanks instead of cylinders.Underwater cinematographer Jordan Klein, Sr. of Florida co-designed such a scuba in 1967, called "Mako", andmade at least a prototype.The Russian Kriolang (from Greek cryo- (= "frost") + English "lung") was copied from Jordan Klein's "Mako"cryogenic open-circuit scuba. Janwillem Bech's rebreather site [4] shows pictures of a Kriolang that was made in1974. Its diving duration is likely several hours. It would have to be filled immediately before use.SCAMP (Supercritical Air Mobility Pack) [5] is an out-of-water liquid-air open-circuit breathing set designed byNASA by adapting space suit technology. Its maker claims that a man wearing it can crawl through a hole50 centimetres (20 in) square.

Rebreathers

An Inspiration rebreather seen from the front

With rebreathers, the gas the diver exhales is stored between breaths ina "counterlung". In some rebreathers, one-way valves direct the gasthrough a "loop". In other rebreathers, the inhaled and exhaled gas goesback and forth along a single tube: this is called the pendulum system.The oxygen consumed by the diver is replaced, nearly always from acylinder. The exhaled carbon dioxide generated by the diver isremoved by passing the gas through a "scrubber" — a canister full ofsoda lime, making the gas fit to be re-inhaled. This type of scubaequipment is known as closed circuit.

Since 80% or more of the oxygen remains in normal exhaled gas, andis thus wasted, rebreathers use gas very economically, making longerdives possible and special mixes cheaper to use at the expense of morecomplicated technology and more experience and longer training.There are three variants of rebreather — oxygen rebreathers,semi-closed circuit rebreathers, and fully closed circuit rebreathers.

The rebreather's economic use of gas, typically 1.6 litres (0.06 cu ft) ofoxygen per minute, allows dives of much longer duration than is possible with open circuit equipment where gasconsumption is typically ten times higher. Oxygen rebreathers have a maximum operating depth of around 6 metres(20 ft), but several types of fully closed circuit rebreathers, when using a helium-based diluent, can dive deeper than100 metres (330 ft). The main limiting factors on rebreathers are the duration of the carbon dioxide scrubber, whichis generally at least 3 hours, and that the scrubber gets less efficient at depth because the scrubber's inside is morecrowded with diluent molecules, hindering the carbon dioxide molecules from reaching the absorbent as quickly.

Scuba set 6

Duration of a diveThe duration of an open-circuit dive depends on factors such as the capacity (volume of gas) in the diving cylinder,the depth of the dive and the breathing rate of the diver, which dependent upon activity levels, size, and experienceamong other factors. New divers frequently consume all the air in a standard "aluminum 80" cylinder in 30 minutesor less on a dive, while experienced divers frequently take 60 to 70 minutes.An open circuit diver whose breathing rate at the surface (atmospheric pressure) is 15 litres per minute will consume3 x 15 = 45 litres of gas per minute at 20 metres. [(20 m/10 m per bar) + 1 bar atmospheric pressure] × 15 L/min =45 L/min). If an 11 litre cylinder filled to 200 bar is used until there is a reserve of 17% there is (83% × 200 × 11) =1826 litres. At 45 L/min the dive at depth will be a maximum of 40.5 minutes (1826/45). These depths and times aretypical of experienced sport divers leisurely exploring a coral reef using 200 bar aluminum cylinders rented from acommercial sport diving operation in most tropical island or coastal resorts.A semi-closed circuit rebreather dive is about three times the length of the equivalent open circuit dive; gas isrecycled but fresh gas must be constantly injected to replace at least the oxygen used, and any excess gas from thismust be vented. Although it uses gas more economically, the weight of the rebreathing equipment means the divercarries smaller cylinders. Still, most semi-closed systems allow at least twice the duration of open circuit systems(around 2 hours).An oxygen rebreather diver or a fully closed circuit rebreather diver consumes about 1 litre of oxygen per minute.Except during ascent or descent, the fully closed circuit rebreather that is operating correctly uses no or very littlediluent. So, a diver with a 3 litre oxygen cylinder filled to 200 bar who leaves 25% in reserve will be able to do a 450minute = 7.5 hour dive (3 L × 200 bar × 0.75 / 1). The life of the soda lime scrubber is likely to be less than this andso will be the limiting factor of the dive.In practice, dive times for rebreathers are more often influenced by other factors, such as water temperature and theneed for safe ascent (see decompression sickness).

Air cylindersAir cylinders used for scuba diving come in various sizes and materials and are typically designated by material —usually aluminium or steel. In the U.S. the size is designated by how much air they contain when expanded to 1atmosphere, 80, 100, 120 cubic feet, etc., with the most common being the "Aluminum 80" which will give anaverage experienced diver from 40 to 60 minutes of dive time under common dive conditions. In Europe the size isgiven as their internal volume (10 liter, 12 liter, etc.).Air cylinder pressure will vary according to the type of material used, ranging from 200 bar (2900 psi) up to 300 bar(4400 psi).Aluminium cylinders are less expensive than steel and have been known to last for 20 years with standard regularmaintenance. The drawback is that an aluminium cylinder is thicker and bulkier than a steel cylinder of the samecapacity, which means the diver would need to carry more weight. Many steel cylinders also accept higher pressurefills, carrying more air for the same displacement of cylinder.Compressed air diving cylinders are sometimes colloquially called "tanks", although the proper technical term forthem is "cylinder".

Scuba set 7

Underwater alternatives to scubaThere are alternative methods that a person can use to survive and function while underwater, including:• free-diving - swimming underwater on a single breath of air.• snorkeling - a form of free-diving where the diver's mouth and nose can remain underwater when breathing,

because the diver is able to breathe at the surface through a short tube known as a snorkel.• surface supplied diving - originally used in professional diving for long or deep dives where an umbilical line

connects the diver with the surface providing breathing gas, and sometimes warm water to heat the diving suit,and usually nowadays voice communications. Some tourist resorts now offer a surface supplied divingarrangement, trademarked as Snuba, as an introduction to diving for the inexperienced. Using the same type ofequipment as scuba diving, the diver breathes from compressed air cylinders, which float on a free floating raft atthe surface, allowing the diver only 20–30 feet (6–9 m) of depth to travel.

• Atmospheric diving suit - an armored suit which protects the diver from the surrounding water pressure.• Liquid breathing - so far, in the real world, liquid breathing for humans is only laboratory experiments, and (one

lung at a time) medical treatment. It has possibilities of being used for very deep diving. It is memorablyportrayed in the film The Abyss.

• Artificial gills (human) - these are mostly science fiction. In the real world they have to process a massive amountof water to extract enough oxygen to supply an active diver, and processing this much water takes a great deal ofenergy (possible for cold-blooded fish, but harder for humans with higher metabolic rates). But see Like-A-Fishfor an attempt to develop real artificial gills for divers.

Breathing sets used out of waterBreathing sets operating on the above principles are not only used underwater but in other situations where theatmosphere is dangerous (little oxygen, poisonous etc).• Firefighting• Other jobs out of water, e.g., welding in a confined space• Mining, especially mine rescue• Operations in enclosed or poorly ventilated areas, e.g., large fluid or gas containers.These breathing sets are nowadays called SCBA (Self Contained Breathing Apparatus) (The initials SCBA have hadother meanings). The first open-circuit industrial breathing sets were designed by modifying the design of theCousteau aqualung.Industrial rebreathers have been used since soon after 1900.rebreather technology is also used in space suits.

HistoryToday's scuba sets are mostly similar to the ideas suggested by Alexander Lodygin many years before the termappeared.A predecessor to scuba gear, the Momsen lung, was used as emergency escape gear by interwar and World War IIAmerican submariners.French Navy lieutenant Yves le Prieur (1885–1963) invented in 1923 a manually-controlled open-circuit SCUBAand founded the first sport SCUBA diving club in the 1920s.French Navy commander Louis de Corlieu invented the swimming fin in 1933.Jacques-Yves Cousteau and Emile Gagnan invented the first commercially successful automatically-controlled open circuit type of SCUBA diving equipment, the Aqua-Lung (often spelled "aqualung") in 1943. Among the things that prompted Cousteau to develop efficient air-breathing diving free-swimming diving gear, were two oxygen toxicity

Scuba set 8

accidents that he had with rebreathers. The Cousteau Gagnan patent was licensed to Siebe Gorman of England. SiebeGorman was allowed to sell in Commonwealth countries, but had difficulty in meeting the demand and the U.S.patent prevented others from making the product. Ted Eldred of Melbourne, Australia met this demand bydeveloping the single hose regulator used today. Ted sold his first Porpoise Model CA single hose scuba in early in1952.Another SCUBA pioneer was John Haven "Jack" Emerson, who also developed the iron lung and other breathingapparatus.Before 1971 all breathing sets including scuba came with a plain harness of straps with buckles like on a rucksack orspray-tank-pack. The buckles were usually quick-release. Many did not have a backpack plate, but the cylinderswere held directly against the diver's back. Sport scuba usually had quick-release fastenings instead of ordinarybuckles. The harnesses of many diving rebreathers made by Siebe Gorman included a large back-sheet of strongreinforced rubber.In the beginning scuba divers dived without any buoyancy aid. In emergency they had to jettison their weights. In the1960s adjustable buoyancy life jackets for aqualung-type scuba became available; one early make was Fenzy. TheABLJ is used for two purposes, one to adjust the buoyancy of the diver to compensate for loss of buoyancy (chieflydue to compression of neoprene wetsuit) and more importantly as a life jacket that can be rapidly inflated even atdepth. It was put on before putting on the cylinder harness. The first were inflated with a small carbon dioxidecylinder, later with a small air cylinder. An extra feed from the first stage regulator lets the life jacket be controlledas a buoyancy aid.

AccessoriesIn modern scuba sets, a buoyancy compensator (BC) or buoyancy control device (BCD), such as a back-mountedwing or stabilizer jacket (otherwise known as a "stab jacket"), is built into the scuba set harness. Although strictlyspeaking this is not a part of the breathing apparatus, it is usually connected to the diver's air supply, in order toprovide easy inflation of the device. This can usually also be done manually via a mouthpiece, in order to save airwhile on the surface. The bladders inside the BCD inflate with air from the "direct feed" to increase the volume ofthe SCUBA equipment and cause the diver to float. Another button deflates the BCD and decreases the volume ofthe equipment and causes the diver to sink. Certain BCD's allow for integrated weight, meaning that the BCD hasspecial pockets for the weights that can be dumped easily in case of an emergency. The aim of using the BCD, whilstunderwater, is to keep the diver neutrally buoyant, i.e., neither floating up or sinking. The BCD is used tocompensate for the compression of a wet suit, and to compensate for the decrease of the diver's mass as the air fromthe cylinder is breathed away.Diving weighting systems, ranging from 2 to 15 kilograms, increase density of the scuba diver to compensate for thebuoyancy of diving equipment, allowing the diver to fully submerge underwater with ease by obtaining neutral orslightly negative buoyancy. While weighting systems originally consisted of solid lead blocks attached to a beltaround the diver's waist, some modern diving weighting systems are now incorporated into the BCD. These systemsuse small nylon bags of lead shot pellets which are distributed throughout the BCD, allowing a diver to gain a betteroverall weight distribution leading to a more horizontal position in the water. There are cases of lead weights beingthreaded on the straps holding the cylinder into the BCD.Many modern rebreathers use advanced electronics to monitor and regulate the composition of the breathing gas.Some scuba sets incorporate attached extra stage cylinders, as bailout in case the main breathing gas supply is usedup or malfunctions, or containing another gas mixture. If these extra cylinders are small, they are sometimes called"pony cylinders". They often have their own demand regulators and mouthpieces, and if so, they are technicallydistinct extra scuba sets.

Scuba set 9

The diver may carry two or more sets of breathing equipment to provide redundant alternative gas systems in theevent that the other fails or is exhausted. Modern recreational rigs most often have two regulators connected to asingle cylinder, in case the primary regulator fails or another diver runs out of air. Some divers instead connect theirbackup regulator to a smaller "pony cylinder" for extra safety, and there are also emergency systems which mount asimple regulator directly to the top of a small cylinder. Rebreather divers often carry a side-slung open-circuit "bailout" to be used in the event the rebreather fails.In technical diving, the diver may carry different equipment for different phases of the dive; some breathing gasmixes may only be used at depth, such as trimix and others, such as pure oxygen, which only may be used duringdecompression stops in shallow water. The heaviest cylinders are generally carried on the back supported from abackplate while others are side slung from strong points on the backplate.When the diver carries many diving cylinders, especially those made of steel, lack of buoyancy becomes a problem.High-capacity BCs are used to allow the diver to control his or her depth.An excess of tubes and connections passing through the water tend to decrease diving performance by causinghydrodynamic drag in swimming.Some diver training organizations and groups of divers teach techniques, such as DIR diving for configuring divingequipment.

Notable early manufacturersNormalair is a firm that is now part of the Honeywell Corporation based in Yeovil (UK). They made an early makeof single-hose aqualung that had a fullface mask as standard. Normalair provided the Deep-Dive 500 rebreather setsused by fictional secret agent James Bond 007 in the 1981 film For Your Eyes Only.Captain Trevor Hampton in the 1950s or 1960s designed an early single-hose aqualung with a full-face mask with acircular window that was a very big, and thus very sensitive demand regulator diaphragm. However, when hepatented it, the Navy requisitioned the patent, and by the time the Navy found no use in the patent and released it, themarket had moved on and he got no use from it.The first commercially successful single hose scuba gear was invented by Ted Eldred of Melbourne, Australia(Porpoise 1952), although many people were working on the problem at the same time.The second company to make single hose scuba was also in Melbourne. It was made by Jim Ager who owned AirDive Pty., Ltd. His regulator was the Sea Bee (1955). Jim still makes scuba regulators and is the longest continuousmaker of single hose scuba in the world.

See also• Timeline of diving technology• List of diver training organizations• See Frogman#Mistakes in fiction for common mistakes in depicting scuba gear.

References[1] Lang, Michael A, ed (2001). DAN nitrox workshop proceedings (http:/ / archive. rubicon-foundation. org/ 4855). Durham, NC: Divers Alert

Network. p. 195. . Retrieved 2008-09-20.[2] http:/ / www. descocorp. com/ fyi_page. htm[3] http:/ / www. scotthealthsafety. com[4] http:/ / www. therebreathersite. nl/ 03_Historical/ cryo_pjotrr. htm[5] http:/ / www. nasa. gov/ missions/ science/ scamp. html

Scuba set 10

External images• www.divingmachines.com (http:/ / www. divingmachines. com/ vintagescuba. html) — Vintage aqualungs

including three-cylinder types

Article Sources and Contributors 11

Article Sources and ContributorsScuba set  Source: http://en.wikipedia.org/w/index.php?oldid=399115714  Contributors: .:Ajvol:., 151.24.190.xxx, 193.167.240.xxx, 62.253.64.xxx, Aitias, AkioMtFuji, Alex.tan, Anastrophe,Andrewa, Andrewcrosby, Andux, Anthony Appleyard, Artemis-Arethusa, AtonX, Bemoeial, Benlambertsen, Bento00, BlaiseFEgan, Bob Jonkman, Bobblewik, Calair, Can't sleep, clown will eatme, Caspian, Chaosite, Chowbok, Chris.n, Christian List, Clotho, Coasting, Conversion script, Corti, Crum375, Csrempert, Curps, CvetanPetrov1940, Cyrius, DDerby, DJ Clayworth, Daniel11,Dave3141592, Davehi1, Donreed, Dulciana, Duncan Jaques, Edlitz36, Elkman, Emdx, Emilyfindley2, Epastore, Epson291, Eric Lemar, Estebs, Evercat, Ewlyahoocom, Exir Kamalabadi,Extraordinary, Fishnogeek, Foobaz, Frontleft, Fuzheado, Gabbe, Gaius Cornelius, Geocachernemesis, GeorgeShaw, Gianfranco, Gibraltarian, Gjs238, God of War, Goodoldave, Gorm, Gparker,Gr0ff, GraemeL, GraemeLeggett, Graevemoore, Graham87, Grunt, Hadal, Harieoal, Henry Flower, Hephaestos, Heron, Hike395, Hmoul, Hydrargyrum, Iridescent, Islandboy99, JHunterJ,Jaggarcia, Jamoche, Janderk, Jarvik, JeffreyN, Jimfbleak, Jorian-Kell, Judik, Juliancolton, K1Bond007, Kevinpurcell, Kosebamse, Kukini, Lawsonsj, Linuxguy3827, Longhair, Luke C,MZMcBride, Magister Mathematicae, Maldivian, Manuel Anastácio, Maphisto86, Marcelo1229, Mark.murphy, Michael Hardy, Mike Rosoft, Mion, Mkill, Mlk, Mojodaddy, Moogyboy, Murtasa,MysteryGirl, NLucey, Naddy, Nathanelrod, Nickj, Nojika, Owain.davies, Patrick, Petruchi41, Petterfs, PierreAbbat, Postdlf, Prmacn, QuantumEleven, Rapierian, RayKiddy, Rdsmith4,RealGrouchy, RedWolf, Redlock, Regulus, RexxS, Rholton, Riana, Rich Farmbrough, Rjwilmsi, Rmhermen, Rossheth, Roturner, SDC, Savidan, Sbharris, SchuminWeb, Scott Sanchez, Scuba,Scuba diva, Sietse Snel, Simon.goodchild, Sirscuba, Skylark of Space, Solitude, Splash22386, Stefan, Stefan Kühn, Telsa, Tempshill, TenOfAllTrades, Thayvian, The Fellowship of the Troll,TheScubaGuy, Timwi, Trekphiler, TwoOneTwo, UT Yorick, UninvitedCompany, UtherSRG, Versageek, Vivenot, Werdan7, Wik, Wikibofh, Wikid77, WpZurp, YUL89YYZ, Yankdownunder,Yosri, Zigger, Zippy, 275 anonymous edits

Image Sources, Licenses and ContributorsImage:Scuba diver1.jpg  Source: http://en.wikipedia.org/w/index.php?title=File:Scuba_diver1.jpg  License: Public Domain  Contributors: Original uploader was Scott Sanchez at en.wikipediaFile:Diving cilinder schematic.JPG  Source: http://en.wikipedia.org/w/index.php?title=File:Diving_cilinder_schematic.JPG  License: Public Domain  Contributors: User:KVDPImage:Aqualung old type.jpg  Source: http://en.wikipedia.org/w/index.php?title=File:Aqualung_old_type.jpg  License: Public Domain  Contributors: Original uploader was Anthony Appleyardat en.wikipediaImage:Aqua lung.jpg  Source: http://en.wikipedia.org/w/index.php?title=File:Aqua_lung.jpg  License: GNU Free Documentation License  Contributors: User Szdavid on fr.wikipediaFile:Plongee-StabilisateurDorsal 20090220 PlaqueLacasse.jpeg  Source: http://en.wikipedia.org/w/index.php?title=File:Plongee-StabilisateurDorsal_20090220_PlaqueLacasse.jpeg  License:GNU Free Documentation License  Contributors: User:EmdxImage:Inspiration front.JPg  Source: http://en.wikipedia.org/w/index.php?title=File:Inspiration_front.JPg  License: Public Domain  Contributors: Original uploader was Mark.murphy aten.wikipedia

LicenseCreative Commons Attribution-Share Alike 3.0 Unportedhttp:/ / creativecommons. org/ licenses/ by-sa/ 3. 0/