Last year, in St. Louis, we had a number of football players on our team and a fairly deep pool at the hotel. The goal was to try to launch kids from the shallow end of the pool nearly straight upwards, high enough that they could touch the ceiling (we figured that it was about 15 feet above the surface of the water) before they landed in the deep end. I was terrible at it because I couldn't time my jumps correctly, but we had a couple of pretty light guys that were amazing jumpers, one of whom came within mere inches of touching the ceiling! This became more of a "hands-on" lesson in physics rather than mindless entertainment
Note: I definitely do
not reccommend even attempting this if you have a small or shallow pool, it is, in retrospect, very dangerous. Even though we took great care (if you can believe it) and no one was hurt, just remember that caution doesn't justify reckless activity.