Walk on water
If you can breath under water theres no need to walk on water unless you're holding a sandwich, because soggy sandwiches are just disgusting. Despite my love of sandwiches I'd have to choose breathing under water simply because of my greater love of not being crucified.
Would the ability to walk on water prevent me from being able to get into water at all?
"I believe the truth is not told between 9 and 5." - Hunter S. Thompson
Well, since the entire world is going to be underwater when the polar ice caps completely melt in 5 years, I'll take the breathing underwater option. I won't have to move out of my house but will have to bolt my tables down so they don't float around.
Life's a journey, pack a lunch!.