We've all seen water dribble from a faucet, but have you ever seen water dribble like a basketball? A new laser etching technique makes metal surfaces superhydrophobic. This general process has applications far more extensive than repelling water.
Interesting question, but no I do not believe such treatment of the hull would make it sink. It wouldn't make the vessel ride any higher in the water (change in displacement). At best, I imagine it might make the ship or boat (submarine) run quieter and faster in the water. And maybe keep the barnacles off. I wonder how high up the hydrophilic treatment can draw water? I doubt it would replace pumps.
For the longest time, I thought the smoother the surface, the lesser the drag. Now we know a rough surface up close is better. So I don't have to wax my car, then...