- Based on the novel by:
- Anthony Thorne
- Screenplay:
- Jay Lewis
- Screenplay:
- Gilbert Hackforth
- Additional scenes and dialogue:
- Bryan Forbes
- Director:
- Jay Lewis
- Producer:
- Antony Darnborough
- Members of 13 Mess:
- 'Puncher' Roberts: John Mills
- Members of 13 Mess:
- 'Knocker' White: Richard Attenborough
- Members of 13 Mess:
- Professor: Bryan Forbes
- Members of 13 Mess:
- Whiskers: Harold Siddons
- Members of 13 Mess:
- Sails: Clifford Mollison
- Members of 13 Mess:
- George: Lionel Jeffries
- Members of 13 Mess:
- Harry: Gordon Jackson
- Members of 13 Mess:
- Joe: Michael Howard
- The Captain's Party:
- Captain: Michael Hordern
- The Captain's Party:
- Commander Digby: Ernest Clark
- The Captain's Party:
- Lieutenant Setley: Thorley Walters
- The Captain's Party:
- Navigation Officer: Patrick Cargill
- The Captain's Party:
- Gunnery Officer: John Forbes-Robertson
- The Captain's Party:
- Officer of the Watch: Roy Purcell
- The Captain's Party:
- Sub-Lieutenant: Kenneth Griffith
- The Captain's Party:
- Master at Arms: Duncan Lamont
- The Captain's Party:
- C.P.O. Blades: Harry Locke
- The Captain's Party:
- P.M.O.: Cyril Raymond
- The Marshal's Party:
- Marshal: Andre Morell
- The Marshal's Party:
- Aide: John Le Mesurier
- The Marshal's Party:
- Interpreter: Ferdy Mayne
- The Vespucci Family:
- Maria: Lisa Gastoni
- The Vespucci Family:
- Paolo: Martin Miller
- The Vespucci Family:
- Mama: Jacenta Dicks
- The Vespucci Family:
- First brother: Carlo Giustini
- The Vespucci Family:
- Second brother: Vince Barbi
- The Vespucci Family:
- Third brother: Vittorio Vittori
- The Vespucci Family:
- The baby: Martyn Garrett
- Naval Personnel:
- The Admiral: D.A. Clarke-Smith
- Naval Personnel:
- S.B.A. Nightingale: Michael Dear
- Naval Personnel:
- First sailor: Barry Foster
- Naval Personnel:
- Second sailor: Vincent Ball
- Naval Personnel:
- American Captain: Robert Ayres
- Naval Personnel:
- Executive Officer: Mark Sheldon
- Naval Personnel:
- Chief Steward: Sam Kydd