What is the primary reason divers practice safety stops during ascent?

The primary reason divers practice safety stops during ascent is to mitigate the effects of nitrogen buildup in the body. As divers descend and spend time at depth, nitrogen from the breathing gas is absorbed into the tissues due to increased pressure. When ascending, it is crucial to allow this nitrogen to be released from the tissues in a controlled manner to avoid decompression sickness, commonly known as "the bends."

Performing a safety stop, typically at around 15 to 20 feet for a few minutes, provides additional time for the excess nitrogen to safely exit the body. This practice is an essential part of dive safety protocols and can significantly reduce the risk of decompression sickness, particularly following deeper or longer dives where nitrogen absorption is greater.

While conserving air supply, avoiding nitrogen narcosis, and maintaining buoyancy control are important aspects of diving safety, they are not the primary reason for conducting safety stops. The specific focus on mitigating nitrogen buildup during ascent highlights the critical balance of avoiding rapid changes in pressure, which is fundamental to safe diving practices.