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Course Outline

How long will the air supply in the cylinder last? The answer to this question will only be an estimation because there are many factors that may affect your breathing rate. The new diver generally has a high breathing rate due to many reasons—one of them being stress. The optimum breathing rate is between 10 and 15 liters per minute (L p/m)/0.35 and 0.53 cubic feet per minute (cu. ft. p/m).

The following are some factors affecting gas consumption.

  • Depth: Boyle’s law shows that gas is compressed underwater by the pressure on it. This means the gas in your lungs is compressed, so you need to take more in to fill the lungs. The deeper we go, the more we need. So, we will use more gas with depth.
  • Efficiency in the water: You need to be streamlined with our equipment to create less drag. You need to use an efficient finning technique and have all your equipment trimmed correctly. Your instructor will help with this in your in-water sessions.
  • Relaxation: The more you are able to relax, the better. This slows your breathing rate, and in turn, you use less gas. Try not to go too fast underwater, and keep your movements slow and deliberate. You will find this comes with practice and reduces your gas consumption.
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