After scuba diving to depths greater than 15 feet, how long must a pilot wait before flying?

• A. 12 hours
• B. 36 hours
• C. 48 hours
• D. 24 hours

Answer: (D)

Diving raises nitrogen levels in your tissues because the increased pressure during the dive dissolves more nitrogen into your blood and tissues. When you ascend, the nitrogen off-gasses slowly, but it doesn’t disappear instantly. Flying adds another factor: cabin pressure at altitude is lower than sea level, so any dissolved nitrogen can come out of solution more quickly and form bubbles in the bloodstream. That combination increases the risk of decompression sickness if you fly too soon.

Because deeper dives (greater than 15 feet) load more nitrogen, the safe wait time before flying is 24 hours. This window gives your body time to off-gas nitrogen sufficiently to reduce the chance of bubbles forming during flight. Shorter waits provide less time for off-gassing, while longer waits are more conservative but unnecessary for this scenario.

So, the recommended waiting period before flying after scuba diving to depths greater than 15 feet is 24 hours.