Well according to my GM the Ocean is considered running, so I don't see why a plane filled with water would be any different. I can't choose my race as the character at risk started out as a human, though since he's currently an outsider, due to his vestige Zceryll, he may not be suseptible to the change anyway.
Just trying to find ways to keep playing this character if he gets changed. I'll have to look up that mask. Otherwise he may need to bind Tenebrous and just walk around in an orb of darkness anytime he needs to go out.