What is the main purpose of performing a safety stop after rapid ascent?

Performing a safety stop after a rapid ascent primarily aims to prevent decompression sickness. During a dive, especially at significant depths, divers are exposed to increased atmospheric pressure, which causes the body to absorb more nitrogen from the breathing gas. If a diver ascends too quickly, the rapid decrease in pressure can lead to dissolved nitrogen forming bubbles in the body, causing decompression sickness, often referred to as "the bends."

By incorporating a safety stop—typically at a depth of around 15 to 20 feet for 3 to 5 minutes—divers provide their bodies with the necessary time to gradually off-gas the excess nitrogen. This period allows for safer nitrogen release and reduces the risk of developing injuries related to decompression sickness. It serves as a precautionary measure to enhance dive safety by allowing physiological adjustments to occur, making it an essential practice for recreational divers and professionals alike.