PADI Divemaster Certification Practice Exam

What factor should divers account for when transitioning from sea level to altitude?

1. Decreased oxygen availability

2. Elevated body nitrogen level

3. Increased risk of decompression sickness

4. Enhanced buoyancy

The correct answer is: Elevated body nitrogen level

When transitioning from sea level to altitude, divers need to be aware of elevated body nitrogen levels. At sea level, divers can safely absorb and eliminate nitrogen while diving and ascending at a controlled rate. However, when they ascend to higher altitudes, the atmospheric pressure decreases more quickly than when descending underwater, which can cause the nitrogen that the body has absorbed during a dive to expand and form bubbles in the bloodstream and tissues. This phenomenon is particularly concerning for individuals who have been diving at compressed depths. While divers do experience decreased oxygen availability at higher altitudes, which is due to the thinner atmosphere, the key issue for divers is the management of dissolved nitrogen in the body. If divers do not account for this and ascend to altitude post-dive without adequate time for nitrogen elimination, they put themselves at significant risk for decompression sickness. So, the emphasis is on understanding how the decrease in pressure at altitude affects nitrogen levels in the body following a dive, which is why recognizing the importance of elevated body nitrogen levels is crucial for divers transitioning from sea level to altitude.