I discovered this method as a young, sexually awakening male at various swimming pools and it is still one of the better masturbation techniques I've ever used.
I like it when the jet of water is hitting "THE" spot on the underneath side just under and near the tip. My hard dick was erupting like mad. I was standing by the edge of the pool (no one else was around) but I know my face was xxx-rated with all that going on!