When is it most critical to perform a safety stop during an ascent?

Performing a safety stop during an ascent is most critical after every dive because it serves as a precautionary measure to help reduce the risk of decompression sickness, also known as "the bends." Safety stops typically occur at a depth of around 15 to 20 feet (5 to 6 meters) for a duration of about three minutes. This procedure allows diver's bodies to off-gas or release nitrogen that may have accumulated during the dive, regardless of its depth.

In this context, while deeper dives may carry a higher risk of decompression issues due to greater nitrogen absorption, safety stops are not exclusive to deep dives. Similarly, safety stops are not contingent upon having a buddy present, nor should they be solely based on the signals from a dive computer. They are a recommended practice for all divers after every dive to enhance safety and promote a gradual ascent, ultimately contributing to safer diving experiences.