When I was a kid, my father used to tell a joke, in which the punch line involved Jesus revealing that the secret to his walking on water was that he knew just where to step in order to find the hidden stones underneath. Never mind that those rocks would have been mighty slippery.
I was reminded of my father's old joke when I recently visited www.waterwalkerz.com. The company sells large inflatable balls, and when one is inside one's "waterwalker" one can "walk on water".
I've also seen "solutions" which basically involved making devices which looked like hybrids between shoes and pontoons.
Either way, I doubt that that's how Jesus did it!