I would have tried to become friends with a shark and hitched a ride on the back of a shark to safety
I'm sure Bruce (the shark from Jaws) would have been happy to bring you back to civilization. Only I think he would have insisted that you ride in his stomach, for your protection of course!
Hopefully a dolphin would be better. A whale did try to help but there was a language barrier.
lol
I'd wait for the Globetrotters to show up and catch their rescue boat.