Ally

When learning to dive, how long do you stay underwater...how deep are you allowed to dive...how much does the average scuba tank hold?

Scuba Mama

Depends

There is not set answer for this question. A diver even with experience and training in the USA should not exceed 130 feet. In Europe the rules are a little different.

Many things effect your air supply, how deep you are, how long you stay at depth, how in shape you are, current, physically condition during the dive (are you working hard), newer diver or experienced.

So the real answer is Depends.