How long does tank last?
A. This sounds like a simple question but is actually very difficult to answer accurately First, the amount of time that it takes a diver to use up all of the air in the dive cylinder is dependent on several factors including the diver’s breathing rate and the depth to which the diver descends (the deeper the dive, the greater the amount of air used) . An average person breathes about .7 cu per minute whereas an experienced diver may have a breathing rate of .5 cubes per minute. Using these numbers it would take an average of 43 – 60 minutes to breathe down a 30 cu ft tank filled at 3000 psi at the surface. At 33 feet that time would be cut in half (two atmospheres). These are only estimates and, as explained, there are many variables that effect how long a tank will actually last.
