At the loading screen, hold R1 + R2 + Right + Square.
Successfully complete the game to unlock a hidden surfboard. Complete the game with the new surfboard to unlock an additional surfboard. This may be repeated to obtain a total of five bonus surfboards. This may also be done in season mode to unlock five more bonus surfboards.
If you were looking for Max Surfing 2000 for PSX cheats, then you might also want cheats for: