There is danger of depth charge or other underwater explosion, the backstroke should be always be used, as it is the best protection against internal injuries from slock waves of underwater concussions. Either the scissor kick or the frog kick may be used. The frog kick unless a man has definite preference otherwise, is probably best.

Another method is to drop the hands down near the hips in the water then turn the hands to about a 45-degree angle away from the body, thumbs downward. With the palms of the hands push the water away from the body. Immediately rotate the hands so that the thumbs are up. The hands now recover, pulling water toward the side of the body. When the hands reach the side they are again rotated until the thumbs are down, and the movements are repeated. The emphasis is on the push-away part of the stroke.

A third method is to place the hand palms on the water, press down on the water several feet depth, and recover again. All these methods, or combinations of them, will be useful at different times.