Air compresses more at greater depths, so you'll go through it faster. You can often stay down 45 minutes to an hour at depths of 20 to 30 feet. On deeper dives, you may only get 15 or 20 minutes. As you get more experienced, you'll learn to conserve air by breathing more slowly, and by minimizing arm movements, which use up energy and air. Soft contact lenses should not be a problem.
Eyeglasses worn under a dive mask are neither fashionable nor practical.
However, it's not too expensive to have your prescription ground into the mask itself. Give us a call and we can help you get it done. All Rights Reserved.