There's a level called Tutorial Boat that I made to help players figure out how to play boat levels.
Ultimately boat levels are just air control levels. There's a video by brionac on youtube called Distance 101 - Air Control Explained. That can help a lot too.

I don't know how to steer my car
how do I do this
if somebody doesn't mind helping me
I really want to play this map it's a interesting concept