Splashdown Cheats

At the options menu, hold R2 and press up, up, down, down, left, right, left, right, square, O, square, O. A secret Cheats screen will appear. Enter any of the following codes:

AllOutAI - Tougher opponents
Hobble - Easier opponents
IBelieve - Race against a UFO in Time Trials
F18 - Race an F-18 in Time Trials
AllChar - Unlock all Characters
Festival - Unlock all video's

Collect 100 balloons in countdown mode.
Game Shark Codes
Master Code (Must Be On) ECB15E9C 141B74EC
Unlock Andy's Movie 4CF58550 1456E7A6
Unlock Haily's Movie 4CF58554 1456E7A6
Unlock Juana's Movie 4CF58558 1456E7A6
Unlock Sebastian's Movie 4CF5855C 1456E7A6
Unlock Rafael's Movie 4CF58560 1456E7A6
Unlock Amman Ra's Movie 4CF58564 1456E7A6
Unlock Kyoko's Movie 4CF58568 1456E7A6
Unlock Jeremy's Movie 4CF5856C 1456E7A6
Arcade Mode Codes
Unlock Seoul 4CF582A0 1456E7A6
Unlock Lake Quilotoa 4CF582A4 1456E7A6
Unlock Nice 4CF582A8 1456E7A6
Unlock Loch Ness 4CF582AC 1456E7A6
Unlock Madrid 2 4CF582B0 1456E7A6
Unlock Kuta Beach 4CF582B4 1456E7A6
Unlock Tokyo 4CF582B8 1456E7A6
Unlock Nile River 4CF582BC 1456E7A6
Unlock Seoul 2 4CF582C0 1456E7A6
Unlock Venice 4CF582C4 1456E7A6
Unlock Bering Straight 4CF582C8 1456E7A6
Unlock Amazon River 4CF582CC 1456E7A6
Unlock Lake Havasu 4CF582D0 1456E7A6

Go to options and press and hold:
r2, up, up, down, down, right, left, right, left, circle, squre, circle, sqaure.

In Options, hold R2 and quickly press Up, Up, Down, Down, Left, Right, Left, Right, Square, Circle, Square, Circle. If done correctly, the Cheat Name screen will appear. Now enter any of the following case-sensitive Codes:
AllChar = All Characters
TopBird = Cannot Get Knocked Off
PMeterGo = Max Performance Meter
Hobble = Hard Tracks with Normal AI
AllOutAI = Expert AI
Festival = All Ending FMV Sequences
IBelieve = Play Time Trials Against A UFO
F18 = Play Time Trials Against a Mini F18
SEADOO = Play Time Trials Against Ghost of Currently Selected Player

Go to Cheat Mode, then enter the name Festival(case-sensitive) to unlock all of the FMV sequences in the game.

Go to loch ness, Scotland.  start racing and in the middle of the
track you will come up to a waterfall.  Submarine under the
waterfall and that's the shortcut.