Lieutenant Braden discovers that Sally, the woman he's been falling in love with, has actually been checking out his qualifications to be a U.S. Navy frogman. He must put his personal life behind him after being assigned to be smuggled into a Japanese-held island via submarine to photograph radio codes.

James Garneras Lt. J. G. Kenneth M. Braden
Edmond O'Brienas Commander Paul Stevenson
Andra Martinas Sally Johnson
Alan Hale Jr.as Lt. Pat Malone
Carleton Carpenteras Lt. Phil Carney
Frank Giffordas Ensign Cy Mount
William Leslieas Lt. Doherty
Richard Bakalyanas Seaman Peck
Edd Byrnesas Pharmacist Mate Ash
Sean Garrisonas Seaman Floyd