Important Dive Theory and Concepts

A major problem exists with any open water course . Although a scuba instructor teaches his students how to react to common emergency scenarios, he cannot anticipate every potential problem that his students may face underwater. Unexpected issues can arise at any point during a dive. A good instructor introduces student divers to the rules of...

Water pressure increases with depth. Water pressure effects almost all aspects of scuba diving, include equalization, buoyancy, bottom times, and the risk of decompression sickness (DCS). Review basic dive theory regarding depth and pressure in scuba diving.

An understanding of buoyancy is key to safe and easy scuba diving. While the concept of buoyancy may be confusing at first, it becomes clearer...

How do scuba divers equalize their ear pressure to avoid ear pain when diving? Learn about the Valsalva maneuver and other ear equalization techniques, as well as how to deal with common equalization problems.

Does the concept of nitrogen absorption confuse you? The sponge analogy is an simple tool to help scuba divers understand how their bodies absorb and off-gas nitrogen when diving.

Boyle's Law, PV=c, is useful in scuba diving because Boyle's Law helps scuba divers predict how air will expand and compress with water pressure. Read an explanation of Boyle's Law and how it applies to scuba diving.

A no-decompression limit (NDL) is a time limit for a scuba dive. If a diver exceeds the no-decompression limit for his dive, he can no longer ascend directly to the surface.

Why do you have so much trouble with your buoyancy when scuba diving? If you find yourself losing control of you buoyancy and floating up, you may have missed a fundamental concept of buoyancy control during your certification course: never inflate to ascend.