What are most recreational scuba tanks filled with?
AnswerCompressed air
Standard tanks hold filtered compressed air, not pure oxygen.
Outdoors · Facts & stats
Scuba facts & stats
7 fact-checked facts about scuba diving and the underwater world, each with the reason behind it. 5 more are in today's round and join this page after it closes.
The basics
Which device delivers air from the tank at breathable pressure?
AnswerRegulator
The regulator reduces tank pressure to what a diver can breathe.
Going deeper
Who co-invented the Aqua-Lung with Emile Gagnan?
AnswerJacques Cousteau
Cousteau and Gagnan developed the Aqua-Lung.
Pressure rises by about one atmosphere for every how many meters of seawater?
Answer10 meters
Every 10 meters (about 33 feet) of seawater adds roughly one atmosphere.
In scuba gear, what does BCD stand for?
AnswerBuoyancy control device
A BCD lets divers adjust buoyancy by adding or releasing air.
Expert level
Which gas law explains why air spaces shrink as a diver descends?
AnswerBoyle's law
Boyle's law says gas volume falls as pressure rises.
What is a breathing mix of helium, oxygen and nitrogen called?
AnswerTrimix
Trimix blends three gases for deep technical diving.
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