What does a safety stop entail during a dive?

A safety stop is a critical part of dive safety that involves pausing at a depth of approximately 15 to 20 feet for around 3 minutes before ascending to the surface. This practice allows divers to off-gas excess nitrogen that their bodies may have absorbed during the dive, significantly reducing the risk of decompression sickness, commonly known as "the bends."

By stopping at this specific depth, divers give their bodies an opportunity to safely eliminate nitrogen and avoid rapid changes in pressure as they ascend to the surface. This procedure is particularly important for dives that exceed certain depths or durations.

The other options do not correctly describe the safety stop. A brief pause at the surface does not allow for adequate off-gassing. A stop at the bottom of the dive would not provide the necessary benefits associated with decompressing at shallower depths. Finally, a period of rest at any depth lacks the specificity and purpose of the safety stop, which is designed to be conducted at a designated recovery depth for optimal safety.