- Will Fyffe
- Chief
- Anthony Hulme
- Steve
- E.V.H. Emmett
- Ted / Commentator
- Guy Middleton
- Pierre
- Albert Lieven
- Fritz
- Hugh McDermott
- Sam
- Arthur Goullet
- Ivan
- Engineer Angel
- Self - Engineer Angel, S.S. Tairoa
- Patrick Dove
- Self - Captain Patrick G.G. Dove, S.S. Africa Shell
- Anthony Eden
- Self
- J.E.T. Harper
- Narrator
- Aubrey Jenkins
- Self - Enginer-Officer Aubrey Jenkins, S.S. Doric Star
- David Lloyd George
- Self
- Miles Malleson
- Minor Role
- Guglielmo Marconi
- Self
- First Officer Murphy
- Self - First Officer F.M. Murphy, S.S. Tairoa
- Charles Pottinger
- Self - Captain Charles Pottinger, S.S. Ashlea
- Jack Raine
- Cutter
- Franklin D. Roosevelt
- Self
- Bill Russell
- Adolf Hitler
- Terry-Thomas
- News reader
- Joachim von Ribbentrop
- Self
- Engineer Walker
- Self - Engineer Walker, S.S. Tairoa
- Pat Williams
- Cutter
- Millicent Wolf
- Secretary
- Robert Beatty
- American newsman in Montevideo
