A young gallerist is in love with two sisters at the same time. In order to solve the problem he decides to invent his own twin-brother.

Sandy Ricks is sent by his mom to Coral Key, a rustic island in the Florida keys, to spend the summer with his uncle Porter Ricks. Sandy dislikes everything about his new environment until a new friend comes into his life, a dolphin named Flipper, that brings uncle and nephew together and leads Sandy on the summer adventure of a lifetime.