Gilligan's Island S03 E16 Take a Dare

"A three-hour tour"

George Barkley enters the ""Take a Dare Contest"". He will receive $10,000 if he can spend a week alone on an island, fending for himself. However, he is not alone on the island on which they drop him. Once again, however, rescue eludes the castaways as Mr. Barkley deduces that he can not tell anyone about the castaways without having to forfeit the $10,000 for not spending the week alone.