Because boats are powered 由 magical monkeys that are held below-deck. They use their telekinetic powers to make the 船, 小船 levitate just high enough above the water to where it appears as if it is floating.
If you've ever heard of the bermuda triangle, that is where boats leave their monkeys, carelessly thinking that they don't need the monkeys. after that, the 船, 小船 sinks and the monkeys carry it into the sky~
