I like how cartoony the bend of the ship is, it really lends wells to the wind waker feel. I think the wheel look like a tire because, if I'm not mistaken, isn't it the wheel from Malon's cart? The change from metal to wood looks great too, you've done the wood masterfully.
What game is the frost isle from? It looks pretty nice, but I don't recognize it. Also, the bridge slats look a bit flat, compared to the rest of the island. They look more pokemon than Zelda. Perhaps if they were wider?