Clive Brook
Captain Tom Armitage
John Clements
Lieutenant Cranford
Edward Chapman
Captain Eckersley
Judy Campbell
Lucy Armitage
Penelope Dudley-Ward
Mabel
Edward Rigby
Mr. Matthews
Allan Jeayes
Commander Blount
Michael Wilding
Dot
Harold Warrender
Lt. Commander Martin
David Hutcheson
Captain Sandeman
George Carney
Bates
Al Millen
Knowles
Charles Farrell
Walker
John Laurie
Gates
George Benson
Parker
Hay Petrie
Minesweeper Skipper
Mervyn Johns
His Mate
Albert Lieven
Commander U.37
John Wengraf
Commander Deutschland
Edward Lexy
Merchantman Skipper
John Glyn-Jones
Mate
John Boxer
German Captain
John Carol
Edmonds
Alec Clunes
Bit Part
Anton Diffring
U-Boat Officer
Derek Elphinstone
Hawkins
Alf Goddard
Bosun's Mate
Stewart Granger
Sutton
Bryan Herbert
Signals Yeoman
Patrick Holt
Holt
James Knight
Admiral
Maire O'Neill
Mary Hogan
Charles Rolfe
Peacock - Wardroom Steward
Harry Terry
Sailor
Charles Williams
'Shorty' Howard
Howard Lang
Gunnery Officer (uncredited)
Crew
