I never thought about it this way...that other kids watched and none helped me...only now that you say so!
He was a bully and everyone was frightened of him, overweight, a bit like a Sumo ringer.
But my Dad was tall and heavy too and really frightening when he got angry!
What I did think about was this:
If I had drowned, my parents would probably never have found out that I was murdered! They would have found me dead in the water, and my parents would have been told: Drowned!
Imagine!! It would have destroyed them. They had already lost my second brother.
What remained with me was am increased sense of caution, so they would not lose me.