What is the purpose of making a safety stop during ascent?

The purpose of making a safety stop during ascent is primarily to prevent decompression sickness. As divers ascend, the pressure around them decreases, causing dissolved nitrogen in their bodies to form bubbles if they ascend too quickly. These bubbles can lead to decompression sickness, commonly known as "the bends," which can cause a variety of serious health issues.

By incorporating a safety stop—typically at a depth of 15 to 20 feet for a duration of 3 to 5 minutes—divers allow time for their bodies to safely off-gas the built-up nitrogen. This controlled and gradual ascent helps reduce the risk of bubble formation and the potential harmful effects of decompression sickness.

Although the other options relate to aspects of diving, such as adjusting buoyancy or equalizing pressure, they do not capture the primary safety motivation for making a safety stop. Adjusting buoyancy is more relevant during the descent and ascent phases, while equalizing pressure addresses the pressure changes experienced at greater depths. Checking communication devices, although important for safety, is not a direct reason for the safety stop itself.