Clive BrookCaptain Tom Armitage John ClementsLieutenant Cranford Edward ChapmanCaptain Eckersley Judy CampbellLucy Armitage Penelope Dudley-WardMabel Allan JeayesCommander Blount Harold WarrenderLt. Commander Martin David HutchesonCaptain Sandeman Hay PetrieMinesweeper Skipper Albert LievenCommander U.37 John WengrafCommander Deutschland Edward LexyMerchantman Skipper Anton DiffringU-Boat Officer Bryan HerbertSignals Yeoman Charles RolfePeacock - Wardroom Steward Charles Williams'Shorty' Howard Howard LangGunnery Officer (uncredited) Pen TennysonDirector / Screenplay Wilfred ShingletonArt Direction 
