Stupid idea dreamed up by our swimming teacher so he could have an hour off. The idea was - rather than teach us to swim, he would leave us in the pool and let natural selection sort us out. The Darwinnian approach was helped by the volleyballs that we were allowed to play with. Basically the runt boy was the only child in the pool, and everyone else twatted him with volleyballs from round the edge. It was impossible for him to get out as every time he did he exposed his whole body to the barrage of hard plastic spheres instead of just his head. A terrible situation to find yourself in.