It's ironic in the extreme that even though a diver may be surrounded by millions of gallons of water, dehydration can be a serious problem.

Dehydration occurs when a diver has inadequate water throughout the body. But why is this a problem? Because, as every Freshman biology major learns, water is essential to a dozen critical biochemical processes and biophysical systems.

At the most basic level, water is needed in order for cells to carry out chemical reactions. Tissues require fluid in order to stay plumped and flexible. And water is required in order to produce blood and keep it moving properly throughout the cardiovascular system.

Fluid can be lost through sweat (yes, even underwater) or urination. But the most common and extensive source of water reduction is simply through breathing.

Normal breathing expels considerable moisture into the air. That's obvious when you breath close to a piece of glass. Underwater breathing actually accelerates that effect because the air in scuba tanks is significantly drier than ordinary surface air. Just as heat flows from a warm body to a cooler one, moisture flows from wetter areas to dryer.

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Scuba diving is a great adventure. But it is also inherently risky. Novice divers learn early on during a certification class how to dive safely. That's the only way to enjoy the dive, this time and in the future. Here are some tips on how to stay safe.

Tip number one should be unnecessary, but it's the most important and has to be said: Never screw around during a dive. No practical jokes, no fights - even playful ones, no hide and seek… you can make up the list yourself. Diving is perfectly safe - if you dive responsibly. If you won't, the risk of serious injury or death is real and high - as many friends and relatives of dead divers can attest.

Before you even take a course, or go on your first learning dive, you should have a medical exam. Diving can be safely and enjoyably experienced by anyone from the very young to the elderly. But it requires substantial fitness. You should be in good shape and have moderate or better leg and shoulder muscles.

More on Scuba Guides - Safety Tips for Safe Dives