Richard Attenborough as Dripper Daniels

James Donald as Lt. Richard Jennings, No. 1

Sonny Tufts as Yank Flanagan

Trevor Howard as Lt. Cmdr Hugh Alginon Fraser

Bernard Lee as A.S. 'Stripey' Wood

Dora Bryan as Glad Flanagan

Hugh Williams as Captain David G. Wilson

Robin Bailey as Lt. Michael Grant, Pilot

Meredith Edwards as Jones

John Forrest as Appleby the Captain's Steward

Patric Doonan as Petty Officer Martin

Sid James as Ned Hardy, Landlord Golden Bull

Harold Siddons as Adm. Bartlett

William Russell as Crewman

Joan Rice as June Mallory, WRNS cypher officer

Peter Bathurst as Commander C.E. Spencer

Charles Lloyd Pack as Captain R. G. Bates (Board of Inquiry)

Chris Adcock as Crewman (uncredited)

Tim Turner as Crewman (uncredited)

George Spence as Man in Pub (uncredited)