Wave Race 64
Big Dolphin
To view the big dolphin, you must go to Championship, Normal, then Warm Up. If you do this 20 times consecutively you will see a larger dolphin in Dolphin Park.
Credit Goes To: Rob Bruder via IGN 64

Change Colors
While selecting your jetski, highlight any character and hold Up on the analog stick. Continue to hold until your character and jetski change color.
Credit Goes To: IGN 64
 Big Dolphin
 Change Colors
 Dolphin Ride
 Reverse Courses
 Ride Backwards
 Start w/ Max Power
 Turbo Charge
Dolphin Ride
Select Stunt Mode mode and enter Dolphin Park. Next go through all the rings and perform the following tricks:
  • Handstand
  • Backwards spin
  • Stand with backflip
  • Single backflip off ramp
  • Dive off ramp
  • Barrel roll off ramp in both directions
If you did the trick correctly a dolphin will squeak when you cross the finish line. To ride your dolphin, select Dolphin Park in a Championship Race and hold Down while selecting your racer.
Credit Goes To: IGN 64

Reverse Courses
If you win the gold cup on Expert, you get a Reverse option. Unlike Mario Kart 64 where the tracks are only "mirrored", in WaveRace 64 you can actually run the courses in their opposite direction.
Credit Goes To: Hector Medina via IGN 64

Ride Backwards
To ride backwards, rotate the joystick clockwise and quickly press and hold Down.
Credit Goes To: Pat Macomber via IGN 64

Start with Max Power
At the start of the race, press the Accelerate button immediately before the third beep.
Credit Goes To: Ryan Casey via IGN 64

Turbo Charge
For a faster jetski, hold the gas button immediately before the announcer says "Go!" The closer you are to the announcement, the faster your jetski will go.
Credit Goes To: IGN 64