Scuba tanks hold a finite amount of air, so the amount of time you can stay underwater is directly related to how efficiently you use that air. More time under the surface means more time to photograph reefs and fish, explore shipwrecks or swim with friends. If you pay attention to the way you move and breathe, your dives will become longer and more enjoyable.
Take It Slow
One of the ways that people waste the most air underwater is by swimming too quickly and frantically. This tires out the body, speeds up the heart, and requires you to breathe more heavily. By moving at a smooth, steady pace you can keep your breathing slow, which in turn allows you to stay down longer and get more enjoyment out of your dives.
Watch Your Depth
As your depth increases, so does the pressure of the surrounding water on your lungs. As this pressure builds up, you begin to breathe more often, wasting valuable air. If there is no need to go deeper, then stay shallow where you can conserve air. Even a small decrease in depth can pay off over the course of a long dive, allowing you to stay under for more time.
Breathe Normally
There is no secret technique to underwater breathing. The best way to conserve your tank is to breathe slowly and normally, as you would if you were on dry land. If you find that your normal breathing becomes labored early on in dives, try getting more exercise. Physical fitness can translate into easier breathing for longer periods of time.
Use EANx
Have your tanks filled with EANx. EANx is an abbreviation for Enriched Air Nitrox. This is a special blend of air that is higher in oxygen than surface air. With extra oxygen coming into your lungs with every breath, it's easy to slow down your breathing and conserve your tank. EANx works most efficiently at shallower depths.
