Editing Scuba set (section)

===Open circuit===
<!--target for redirect[[Open circuit scuba]] -->
The gas endurance of open-circuit-demand scuba 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 is dependent on exertion, fitness, physical size of the diver, state of mind, and experience, among other factors.  New divers frequently consume all the air in a standard "aluminum 80" cylinder in 30 minutes or less on a typical dive, while experienced divers frequently dive for 60 to 70 minutes at the same average depth, using the same capacity cylinder, as they have learned more efficient diving techniques.{{citation needed|date=August 2016}}

An open-circuit diver whose breathing rate at the surface (atmospheric pressure) is 15 litres per minute will consume 3 × 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 to be used until there is a reserve of 17% there is (83% × 200 × 11) = 1826 litres available. At 45 L/min the dive at depth will be a maximum of 40.5 minutes (1826/45). These depths and times are typical of experienced recreational divers leisurely exploring a [[coral reef]] using standard 200 bar "aluminum 80" cylinders as may be rented from a commercial recreational diving operation in most [[tropical]] island or coastal resorts.{{citation needed|date=August 2016}}