Start a new game and race one of the Beginner tracks. You must place well enough to enter your initials in to the high score listing. Enter "?PB" (without quotes) and you will unlock every track, and every boat in the game!! (this includes the Tiny Titanic, Blowfish Armed Response, and Chumdinger)
submitted by m'hood
Pause the game, and press B + Y
You can unlock secret tracks for two player mode by winning races in two player mode. If you unlock all the tracks, you start to unlock the bonus boats, until you have all tracks and boats.
Complete all the Beginner tracks. Return to the Main Menu agian hold the L (left trigger) and press A, X, Y, Z.
Timing is important for this, so pay close attention:
Hold L(left trigger) while the game is still loading. When the countdown starts, watch the numbers closely...As the number 3 fades, let go of L and hold R. As the number 2 fades, you have to reverse it so that you are holding L again and have released R. Finally, as the number 1 fades, reverse yet one more time so that you are now holding R
This is the ultra secret Tiny Titanic that everyone is talking about. First you have to place in the top three in all of the Beginner tracks. Then you have to place in the top two of all the medium tracks. Finally, place first in all of the Hard tracks. This unlocks the bonus tracks, but you're not done yet! You have to place first in the first three bonus tracks, which unlocks the The Tiny Titanic.