- Bruce Bennett
- Archie Gibbs
- Erik Rolf
- Kapitaen Ganz, The U-Boat Captain
- John Abbott
- Alfonse Lamont
- John Wengraf
- Gunther Rudehoff, Gestapo Agent
- Robert B. Williams
- Destroyer Commander Tom Bristol
- Sam Ash
- Convoy Ship's Engineer
- Trevor Bardette
- Convoy Ship Commander
- Sven Hugo Borg
- U-Boat Lt. Dorner
- Egon Brecher
- Prof. Van der Brek
- Frederic Brunn
- Kohl
- Anthony Caruso
- Benny, Seaman's Union Hall Man
- Paul Conrad
- Convoy Ship Lt. Nolan
- Ralph Dunn
- American Naval Officer
- Carl Ekberg
- Guard
- George Eldredge
- George Acton, Nazi Spy
- Eric Feldary
- Hans Braustig, Injured Sailor
- Arno Frey
- U-Boat Officer Hagemann
- Terry Frost
- Plane Radioman
- Jack Gardner
- Rinelli
- Gene Garrick
- Pilot
- Frederick Giermann
- U-Boat Torpedo Officer Kerck
- Fred Graff
- Lieutenant Blake
- Fred Graham
- American Lieutenant
- Peter Helmers
- Petty Officer
- Tom Holland
- Guard
- Robert Homans
- Cleric Captain
- Erwin Kalser
- Prof. Biencawicz
- Jimmy Lane
- First Lookout
- Nelson Leigh
- Destroyer Lt. Hagen
- Rolf Lindau
- Sound Man
- George Lloyd
- Mack, Seaman's Union Hall Clerk
- Kenneth MacDonald
- Prof. Hamilton
- John Merton
- Officer Elsner
- Edwin Mills
- Wireless Sparks
- Frederick Pressel
- Depth Sailor
- Neil Reagan
- Seaman Edwards
- Robert L. Stephenson
- Steer Man
- Ray Teal
- C.P.O. Shaw
- John Tyrrell
- Lt. Howard
