John Gregson as Captain Bell - H.M.S. Exeter

Anthony Quayle as Commodore Harwood - H.M.S. Ajax

Ian Hunter as Captain Woodhouse - H.M.S. Ajax

Jack Gwillim as Captain Parry - H.M.N. Z. S. Achilles

Bernard Lee as Captain Dove - M.S. Africa Shell

Lionel Murton as Mike Fowler

Anthony Bushell as Sir Millington Drake, British Minister, Montevideo

Peter Illing as Dr. Guani, Foreign Minister, Uruguay

Michael Goodliffe as Captain McCall, R.N., British Naval Attache, Buenos Aires

Patrick Macnee as Lieutenant Commander Medley, R.N.

John Chandos as Dr. Langmann, German Minister, Montevideo

Douglas Wilmer as M. Desmoulins, French Minister, Montevideo

William Squire as Ray Martin

Roger Delgado as Captain Varela, Uruguayan Navy

Andrew Cruickshank as Captain Stubbs, 'Doric Star'

Christopher Lee as Manolo

Edward Atienza as Pop

April Olrich as Dolores

Peter Finch as Captain Langsdorff, "Admiral Graf Spee"

David Farrar as Narrator

John Le Mesurier as Reverend George Groves - Padre, HMS Exeter

Cyril Luckham as Lieutenant Jasper Abbot, H.M.S. Achilles

George Murcell as Chief Officer, Newton Beach

Anthony Newley as Radio Operator, Tairoa, Prisoner on Admiral Graf Spee

Nigel Stock as Chief Officer, Tairoa, Prisoner on Admiral Graf Spee

Barry Foster as Bill Roper - Capt. Bell's Messenger, HMS Exeter

Ambrosine Phillpotts as Mrs. Millington-Drake, Montevideo

Tony Wager as Lookout, HMS Ajax

Brian Worth as Radio Operator, Doric Star, Prisoner on Graf Spee

Patrick Westwood as Archer, HMS Ajax

Chris Adcock as British Seaman (Prisoner on Graf Spee) (uncredited)

Michael Collins as Chief Yeoman, HMS Ajax (uncredited)

Patrick Jordan as Signalman, Aft-Conning, HMS Exeter (uncredited)

Jeremy Kemp as Gunner, HMS Achilles (uncredited)

Donald Moffat as Swanston - Lookout, HMS Ajax (uncredited)

John Schlesinger as Lieutenant, Graf Spee (uncredited)

Richard Beale as Capt. Pottinger (uncredited)

John Forbes-Robertson as Lt. McBarnett, HMS Exeter (uncredited)

Howard Lang as Guns - HMS Exeter (uncredited)