John Gregson
Captain Bell - H.M.S. Exeter
Anthony Quayle
Commodore Harwood - H.M.S. Ajax
Ian Hunter
Captain Woodhouse - H.M.S. Ajax
Jack Gwillim
Captain Parry - H.M.N. Z. S. Achilles
Bernard Lee
Captain Dove - M.S. Africa Shell
Anthony Bushell
Sir Millington Drake, British Minister, Montevideo
Peter Illing
Dr. Guani, Foreign Minister, Uruguay
Michael Goodliffe
Captain McCall, R.N., British Naval Attache, Buenos Aires
Patrick Macnee
Lieutenant Commander Medley, R.N.
John Chandos
Dr. Langmann, German Minister, Montevideo
Douglas Wilmer
M. Desmoulins, French Minister, Montevideo
Roger Delgado
Captain Varela, Uruguayan Navy
Andrew Cruickshank
Captain Stubbs, 'Doric Star'
Peter Finch
Captain Langsdorff, "Admiral Graf Spee"
Jeremy Kemp
Gunner, H.M.S. Achilles (uncredited)
John Le Mesurier
Reverend George Groves - Padre, HMS Exeter
Cyril Luckham
Lieutenant Jasper Abbot, H.M.S. Achilles
Donald Moffat
Swanston, Lookout, H.M.S. Ajax (uncredited)
George Murcell
Chief Officer, Newton Beach
Anthony Newley
Radio Operator, Tairoa, Prisoner on Admiral Graf Spee
Nigel Stock
Chief Officer, Tairoa, Prisoner on Admiral Graf Spee
Barry Foster
Bill Roper - Capt. Bell's Messenger, HMS Exeter
Ambrosine Phillpotts
Mrs. Millington-Drake, Montevideo
Brian Worth
Radio Operator, Doric Star, Prisoner on Graf Spee
Chris Adcock
British Seaman (Prisoner on Graf Spee) (uncredited)
Michael Collins
Chief Yeoman, HMS Ajax (uncredited)
Patrick Jordan
Signalman, Aft-Conning, HMS Exeter (uncredited)
Jeremy Kemp
Gunner, HMS Achilles (uncredited)
Donald Moffat
Swanston - Lookout, HMS Ajax (uncredited)
John Schlesinger
Lieutenant, Graf Spee (uncredited)
Richard Beale
Capt. Pottinger (uncredited)
John Forbes-Robertson
Lt. McBarnett, HMS Exeter (uncredited)