Cast
Erwin Kalser
Dr. Adolph Behrens
Frank Sully
Tommy Malone
Melville Cooper
Ship's Mate Penney
Stanley Logan
Captain James P. Hollister
Bruce Bennett
Ship's gunnery officer
Frank Baker
Detective
Alan Baxter
Larry Perrin, alias Larry Ross
Edgar Buchanan
Charles Atterbee
John Halliday
John Morgan
Jessie Busley
Mrs. Mudge
Don Beddoe
Ship's Chief Engineer Anderson
Constance Bennett
Christine Blaine
Marjorie Gateson
Mrs. Winslow
Norbert Schiller
Submarine First Officer
Dick Rich
Perrin's Henchman at Dock
Douglas Gordon
Ship's Lookout
Pat O'Brien
Mike Farrough
Olaf Hytten
Agent
Francis Pierlot
Professor Mudge
Wyndham Standing
Man