First you must go to the Hawaii track. When you get to the part where you are underneath a bridge type thing and there are fat stone posts that you can easily run into, before that, if you go totally right, you can break through 2 walls of glass and you end up at an airport. At the end of it there is a wood ramp that leads onto a battleship and if you keep going you will eventually jump onto another ship, then back onto the track.

PS- its really good for when you are racing and need to raise your position.