Looks like it'd be pretty cool once you got going.... sucks that it sinks when you stop though

Some more R+D might just yield something more practical.
Think of the bicycle 100 or whatever years ago, those stupid big front tire things, and the guys with the moustache's. Now people basically ride off cliffs and down mountains with them. A human powered PWC would be pretty sweet if you could move on the water like you can in the woods on a bike....