Dr Phil Harmon is attacked by a shark. He radios to bring a rare blood type that can save his life.

Flipper comes to the rescue when a submarine gets caught on the bottom of the ocean, trapping its occupant who is fast running out of air.

Bud isn't happy with the new woman in his father's life. Feeling alone in the world, Bud stays out in the ocean too late and winds up lost in an underwater cave at high tide.

Despite their best attempts to impress a visiting Congress woman, Porter and the boys are devastated to learn that she plans to close the park.

Bud and Sandy, on a trip with Hap Gorman to his secret fishing grounds, board an abandoned boat, not knowing that a hidden charge of dynamite is about to blow it to pieces.

When Flipper finds a Spanish doubloon on the ocean bottom and brings it to Bud and Sandy, rumours about Spanish Treausures spread quickly and an underwater gold rush ensues.