When does a diver need to perform a controlled swimming ascent?

A controlled swimming ascent is essential for maintaining safety during a dive and is primarily utilized in emergency situations, such as an out-of-air scenario. When a diver experiences an out-of-air situation, it becomes crucial to ascend in a controlled manner to mitigate the risks of decompression sickness and ensure proper air exchange.

During such an ascent, divers must be cautious about their rate of ascent, generally recommended to be no faster than 30 feet per minute, and they should stop at safety stops if applicable. This technique allows for the gradual release of nitrogen from the body, which is particularly important in preventing the bends.

Ascending from depth after reaching maximum depth, navigating underwater, or descending to the bottom do not necessitate the specific technique of a controlled swimming ascent associated with the urgency and care required in an out-of-air emergency. Thus, the emphasis on performing this maneuver is particularly critical in situations where safety cannot be compromised.