A schooner disappears at sea without a trace. Years later, evidence of possible survivors prompts the mother of the schooner's mate Jose to hire a tuna boat to investigate. They discover the lad living happily on a South Seas island, and, when he refuses to leave with them, they abduct him. However, Jose gets revenge by leading the ship into the lair of a mysterious giant manta ray.

• Excelsior Pictures Corp.
• Barry Norton
• Blanche Mehaffey
• Jack Barty
• Terry Grey
• Jack Del Rio
• Mary Carr