How do you defeat boat boss in super Mario bros wii world 8?

For the first part when Bowser is small you have to sprint under him when he jumps very high, you cant hurt him, but i recommend having ice so you can reflect the fireballs, but it is not necessary, you can just doge them. After you hit the switch the floor falls, so if your on multi player make sure they go into there bubble. From there Peach turns into that wizard guy and brings bowser back, only huge. Now you have to sprint as he throw fireballs at you, breaking the walls so you can get through. My best advice is to get the crazy hat (propeller hat idk what you call it) when you can towards the end, and then you hit the switch.

:)) hope this helps!