What is the purpose of decompression stops?

• A. Increase bottom time
• B. Improve buoyancy control
• C. Allow safe elimination of inert gases
• D. Reduce the need for decompression

Answer: (C)

Decompression stops exist to allow inert gases that have dissolved in the body's tissues under pressure to be eliminated safely as you ascend. When you dive, nitrogen dissolves into tissues and the bloodstream. As you rise and ambient pressure drops, that nitrogen must come out of solution gradually. If the ascent is too fast, bubbles can form in tissues and blood, leading to decompression sickness. Pausing at specific depths gives time for the different tissue compartments to off-gas in a controlled way, matching the surrounding pressure and minimizing bubble formation. So the purpose is to manage off-gassing to keep the ascent safe.