Leslie Banks as Taylor

Michael Redgrave as Russian

Will Hay as Skipper

John Mills as Tom

Bernard Miles as Royal Navy Mate

Michael Rennie as George

Frank Cellier as Schneider

Robert Morley as Von Geiselbrecht

Alfred Drayton as Direktor

Marius Goring as German Propaganda Officer

Austin Trevor as U-boat Captain

Albert Lieven as Gunter

Leif Konow as Dane