Editing Scuba set (section)

{{short description|Self-contained underwater breathing apparatus}}
{{about||self contained breathing apparatus intended for use out of the water (SCBA)|Self-contained breathing apparatus}}
{{for |the uses of a scuba set|Scuba diving|Recreational diving|Technical diving|Professional diving}}
{{Infobox diving equipment
|name         = Scuba set
|image        = Diver on the wreck of the Aster PB182648.JPG
|alt          = <!-- Wikipedia:Alternative text for images -->
|caption      = Diving with a recreational open-circuit scuba set
|acronym      = Scuba
|other_names  = {{ubl|Scuba gear|Open-circuit scuba|Diving rebreather|Aqualung|Bailout set}}
|uses         = Providing an underwater diver with an autonomous breathing gas supply
|inventor     =
|manufacturer =
|model        =
|related      =
}}

A '''scuba set''', originally just '''scuba''', is any breathing apparatus that is entirely carried by an [[underwater diving|underwater diver]] and provides the diver with [[breathing gas]] at the ambient pressure. ''Scuba'' is an [[anacronym]]<!-- Yes it's actually called an 'anacronym'. a word that has acronymic origin but is generally no longer treated like conventional acronyms and is used syntactically like any other word, without reference to the original expansions Please don't change it to 'acronym' --> for '''self-contained underwater breathing apparatus'''. Although strictly speaking the scuba set is only the diving equipment that is required for providing breathing gas to the diver, general usage includes the harness or rigging by which it is carried and those accessories which are integral parts of the harness and breathing apparatus assembly, such as a jacket or wing style [[Buoyancy compensator (diving)|buoyancy compensator]] and instruments mounted in a combined housing with the pressure gauge. In the looser sense, scuba set has been used to refer to all the [[diving equipment]] used by the scuba diver, though this would more commonly and accurately be termed [[scuba equipment]] or [[scuba gear]]. Scuba is overwhelmingly the most common underwater breathing system used by recreational divers and is also used in [[professional diving]] when it provides advantages, usually of mobility and range, over [[surface-supplied diving]] systems and is allowed by the relevant legislation and code of practice.

Two basic functional variations of scuba are in general use: open-circuit-demand, and rebreather. In open-circuit demand scuba, the diver expels exhaled breathing gas to the environment, and each breath is delivered at ambient pressure, on demand, by a diving regulator which reduces the pressure from the storage cylinder. The breathing gas is supplied through a demand valve; when the diver inhales, they reduce the pressure in the demand valve housing, thus drawing in fresh gas.
In [[Rebreather diving|rebreather]] scuba, the system recycles the exhaled gas, removes carbon dioxide, and compensates for the used [[oxygen]] before the diver is supplied with gas from the breathing circuit. The amount of gas lost from the circuit during each breathing cycle depends on the design of the rebreather and depth change during the breathing cycle. Gas in the breathing circuit is at ambient pressure, and stored gas is provided through [[Diving rebreather#Closed circuit mixed gas rebreathers|regulators]] or [[Diving rebreather#Semi-closed circuit rebreathers|injectors]], depending on the design.

Within these systems, various mounting configurations may be used to carry the scuba set, depending on application and preference. These include: back mount, which is generally used for recreational scuba and for bailout sets for surface supplied diving; side-mount, which is popular for tight cave penetrations; sling mount, used for stage-drop sets; decompression gas and bailout sets where the main gas supply is back-mounted; and various non-standard carry systems for special circumstances.

The most immediate risk associated with scuba diving is drowning due to a failure of the breathing gas supply. This may be managed by diligent monitoring of remaining gas, adequate planning and provision of an emergency gas supply carried by the diver in a [[bailout cylinder]] or supplied by the [[Buddy diving|diver's buddy]], and the skills required to manage the gas sources during the emergency.