When i was on holiday in Cancun, we were getting pestered by the entertainer's round the pool to enter the the daft comps to keep everyone entertained. I finally gave in and it turned out to be a bellyflop competition off a diving board. sh*t myself but could not back out. Turns out i never felt a thing, didn't even sting. If you can land flat the surface tension bends instead of braking like landing on a jelly.
Wouldn't do it again though.