The Kelp Caves are in essence a large puzzle. Built around opening gates and raising trampolines, much of the level is blocked off in one way or another. This includes a camper and crystal, both of which are stuck behind a gate.
In the room with the gate, it is possible to clip out of bounds near the camper. By wedging SpongeBob in a weird bit of geometry between a rock and the wall while Cruise Boosting, it is possible to L-Clip and reach the cave camper. Additionally, it is possible to ledge grab into the room with the camper, otherwise the player must go to the right, activate a checkpoint, and drown to enter the room. This skips the need to open the gate.