T&C Surf Designs: Thrilla's Surfari Cheats

Press Left, Up, Right, Up, Right, Down, A at the title screen.

In the first surfing stage (1-3), at the beginning, you can make a huge jump that will land you in a warp to Level 3-1 with a bunch of extra lives and full life. Simply surf near the top of the screen, down the first stream. When you reach the waterfall, jump as far as you can to the right. If done correctly, you'll fall off the screen and land on the right side of the waterfall instead of the left. Keep going right and you will land in the secret warp zone.