An experienced diver will often times panic when, due to lack of attention or equipment failure, their air supply stops. When I was learning and practicing budd

An experienced diver will often times panic when, due to lack of attention or equipment failure, their air supply stops. When I was learning and practicing buddy breathing we were taught to hand the diver needing air the regulator from your mouth and then you go for your spare mouthpiece simply because they will often focus completely on the working air supply in your mouth -- to the point of just pulling it from you.