When should a diver perform a safety stop during ascent?

A safety stop during ascent is typically performed at a depth of 15-20 feet for 3-5 minutes. This practice is crucial for divers because it helps to off-gas nitrogen absorbed during the dive, reducing the risk of decompression sickness (DCS). At this depth, the pressure is low enough to allow for effective nitrogen elimination while still being shallow enough to ensure the diver can easily surface if there is an emergency.

The 3-5 minute duration provides sufficient time for nitrogen to leave the tissues, which is especially important following deeper or longer dives. This safety protocol acts as a precautionary measure, benefiting divers regardless of their specific dive profile.

Being aware of the recommended depths and times for safety stops is essential for divers to ensure their safety and well-being. The other options generally either suggest inappropriate depths or durations or do not reinforce the importance of a safety stop after standard dive durations.