Get pissed off at the kelp
From Create Your Own Story
When you do, the kelp abruptly severs itself. You are not suprised. A lot of weird things have happened to you. When Aunt Petunia shaved your hair, it grew back in one day. When she tried to fit you into Dudley's ghastly old sweater, it shrunk so much that it looked like a puppet. And of course, the snake incident. You swim up to the island, and look around.