George, The Man, The Doorman, and Hundley go out on the sea for a day on the doorman's sailboat. But, when the boat sail breaks, the group stops at an artificially rendered tropical island to look for parts to fix it. Soon, George's curiosity and Hundley's habit to keep everything neat and orderly causes the boat to wash out to shore with them in it. They find their way back to the island but must now find The Man With The Yellow Hat and The Doorman.