Mike and Tony Petrakis are a Greek father and son team who dive for sponges off the coast of Florida. After they are robbed by crooks, Arnold and the Rhys brothers, Mike decides to take his men to the dangerous 12-mile reef to dive for more sponges. Mike suffers a fatal accident when he falls from the reef leaving Tony to carry on the business. But now he has a companion, Gwyneth Rhys.
Robert Wagner
as Tony Petrakis
Terry Moore
as Gwyneth Rhys
Gilbert Roland
as Mike Petrakis
J. Carrol Naish
as Socrates Houlis
Richard Boone
as Thomas Rhys
Angela Clarke
as Mama Petrakis
Peter Graves
as Arnold Dix
Jay Novello
as Sinan
Jacques Aubuchon
as Demetrios Sofotes
Gloria Gordon
as Penny Petrakis
Harry Carey, Jr.
as Griff Rhys
Rock Hudson
as Narrator (uncredited)
