I don't know if things have changed but 45 years ago everyone at the local YMCA was nude when using the pool. Old and young alike. I started swimming at the Y when I was 8 or 9 but I never felt uncomfortable until I turned 11. That is when I started puberty. By the next year my pecker size increased a full 3 inches and it was surrounded by a thin band of dark hair. I started to notice that a couple of the older men looking my way. Nothing ever happened but I stopped going to the Y. In retrospect I'm glad I did.