Swim through an island

From Glitches

From the game Donkey Kong 64 for the Nintendo 64.

In DK Isles, go underwater. Now, swim towards the middle of that island that holds the big caged guy (I forget his name!). There's a line around it that you should try to head straight at. You'll go through it and be inside of the island. Unfortunately, you can't jump through it from the bottom, since it has a barrier.

Submitted by: kornyhatemachine