What a cool idea! I'd have to say that's my favorite Zelda game. I know there is some un-chartered territory in that game, but maybe you could quilt it from the path your boat has to make to get from island to island.
Isn't there also some nasty stuff that attacks you in the water? I'm thinking of a water spout or something like that. Maybe you could quilt in those little details too.
Just a thought.