I think the term we're looking for is "Aquaphobic", the fear of water. Hydrophobic, means something that repels water, E.g. this glass is Hydrophobic, so water droplets can't form on the surface. But thats neither here nor there. I really have a hard time understanding (in terms of game logic) how can can breathe in space, where there is NO oxygen, or any other type of gas, but he can't breathe in water, where there is a small amount of oxygen dissolved. Odd, I just think he's a little wimp and...well....that Sonic X video can explain it better than I can.