How should a diver react in an out-of-air situation?

In an out-of-air situation, signaling a buddy and switching to an alternate air source is the most effective and safest response a diver can take. This situation implies that the diver has exhausted their air supply and needs to find a means of breathing to prevent life-threatening consequences such as hypoxia or drowning. By signaling a buddy, the diver alerts them to the emergency and facilitates a quick air supply exchange.

Using an alternate air source allows the diver to maintain safe breathing and control their ascent, reducing the likelihood of panic and accident during a critical moment. This coordinated response prioritizes safety and provides a practical solution, keeping both divers aware and involved.

While ascending immediately to the surface may seem like a logical response in an emergency, it can lead to serious risks, such as decompression sickness or barotrauma if done without proper ascent procedures. Staying calm and continuing the dive is counterproductive since the diver is out of air and thus cannot sustain the dive safely. Attempting to swim to a shallow area without an adequate air supply poses significant risks and could lead to panic or accidents, especially if the diver has to perform this action while breathless. Thus, the approach of signaling a buddy and using an alternate air source is the most appropriate action in response