To make your skateboard float, ride your skateboard up to a car and when the drive sign comes up, quickly press the control button.

You'll be in the car and your skateboard will be in mid-air!!!

OK I'll show you how to walk on water
first ya get on your skateboard and ride strait towards water (it works best at the dock).

Start on a hill and ride down it when you get right at the surface of the water jump and while your in the air put your skateboard in your backpack and if you do it at the correct time then you will land on the water and beable to walk on it but you cant ride you skateboard on it.