What should divers do if they experience a rapid ascent?

If divers experience a rapid ascent, the appropriate response is to immediately descend to the last safe depth. This action is crucial because a rapid ascent can lead to serious decompression sickness or an air embolism due to the sudden reduction in pressure. When divers ascend too quickly, nitrogen bubbles can form in their tissues, leading to potentially life-threatening conditions.

Descending to the last safe depth allows the diver to stabilize their body and facilitates the reabsorption of nitrogen before making a safer ascent. After descending, divers should monitor their conditions and consider following proper decompression procedures if necessary. This approach prioritizes the diver's safety and minimizes risks associated with rapid changes in depth.

In contrast, continuing to ascend slowly may not adequately address the risks already encountered due to the initial rapid ascent, and surfacing quickly without stopping is usually dangerous. Performing a controlled drift could help in some contexts, but it doesn’t directly address the immediate danger posed by the rapid ascent. Thus, descending to a safe depth is the most prudent and effective response to mitigate the dangers associated with a rapid ascent.