Norman Wisdom

as Ordinary Seaman Norman Puckle

Ian Hunter

as Admiral Sir Bryanston Blyth

David Lodge

as Chief Petty Officer Knowles

Robert Urquhart

as Commander Clayton

Edward Chapman

as Mr. Philpots

Eddie Byrne

as Petty Officer Filkins

Peter Jones

as Diving Instructor

John Le Mesurier

as Prosecuting Counsel