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

The basic purpose of a safety stop during ascent is to release excess nitrogen from the body. When divers are underwater, they absorb nitrogen from the air in the breathing gas due to the increased pressure. As divers ascend, the pressure around them decreases, which can lead to nitrogen bubbles forming if they ascend too quickly. A safety stop, typically performed at around 15 feet (5 meters) for about three minutes, provides the body with extra time to off-gas the excess nitrogen safely and reduces the risk of decompression sickness, commonly referred to as "the bends." This practice effectively allows divers to safely manage and mitigate the accumulation of nitrogen, making it a critical part of dive safety.