Tom Swift and His Diving Seacopter

In his unique invention the Ocean Arrow, an "underwater helicopter," Tom Swift Jr. embarks on a precarious search for a lost rocket from space.

The rocket, containing evidence of living things on another planet, was directed to Swift Enterprises for scientific study. But its course was mysteriously changed while the rocket was hurtling toward earth - and its landing site is unknown!

Tom suspects that the rocket lies underwater, somewhere off the coast of South America, Accompanied by his friends, Bud Barclay and Chow Winkler, and two expert oceanographers, the young inventor sets out in his diving seacopter to locate the rocket.

But a group of unethical scientists have uncovered a clue to this valuable treasure from space. In their own undersea craft, they try to thwart Tom in his attempt to claim the rocket which rightfully belongs to Swift Enterprises.

Unexpected dangers confront the Swift expedition every mile of the seraph for the scientific prize. When the Ocean Arrow is trapped in a crushing, underwater landslide, Tom and his companions nearly lose their lives.