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Old 03-11-2014, 11:19 PM   #33
SpearMax
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Join Date: May 2005
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Re: Educational Discussion of Michael Reed Accident/Incident

When diving with the potential to go deep beyond the recreational diving limit of 130 feet, one must realize that they can go though the gas in their tank rapidly. Here is an explanation from an Internet reference source:

"As a scuba diver descends, the pressure around him increases (learn how depth effects pressure in scuba diving). This increase in pressure does not effect the air inside the diver's scuba tank because it is already compressed to a very high pressure and the scuba tank is a rigid container. However, the water pressure does compress air that exits the tank and flows through the scuba diver's regulator hoses and second stages. The quantity of air that fills 1 cubic foot of space at the surface will only fill ˝ a cubic foot of space at a depth of 33 due to the compression of water. Therefore, the quantity of air that fills a diver's lungs at the surface will only half fill his lungs at 33 feet. The deeper a diver goes, the greater the quantity of air required to fill his lungs with each breath, and the more quickly he will use up the air in his tank.

Air Consumption Rate All other factors being equal, a diver's air consumption rate, also called his Surface Air Consumption Rate (SAC rate) or Respiratory Minute Volume (RMV), will determine how long the air in his tank will last compared to the average diver. A diver with large lung volume (tall or large people) will require more air than a petite or short person with a smaller lung volume and will usually have a higher air consumption rate. A variety of factors effect an individual's air consumption rate, including stress, experience level, buoyancy control, and the amount of exercise the diver does on a dive.

Relaxed, slow, and deep breathing is usually the best way for a diver to reduce his air consumption rate."


Continue Reading: http://scuba.about.com/od/scuba101/p...-Tank-Last.htm
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Last edited by SpearMax; 03-12-2014 at 09:06 AM.
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