Mystery Liner

Noah Beery

— Capt. John Holling

Astrid Allwyn

— Lila Kane

Edwin Maxwell

— Major Pope

Gustav von Seyffertitz

— Inspector Von Kessling

Ralph Lewis

— Prof. Grimson

Cornelius Keefe

— First Officer Cliff Rogers

Zeffie Tilbury

— Granny Plimpton

Boothe Howard

— Capt. Downey

Howard Hickman

— Dr. Howard

Jerry Stewart

— Edgar Morton

John M. Sullivan

— Watson

George 'Gabby' Hayes

— Joe, the Watchman

George Cleveland

— Simms, the Steward

Raymond Brown

— Spy Chief (uncredited)

Gordon De Main

— Commander Bryson (uncredited)

Olaf Hytten

— Grimson's Aide (uncredited)

George Nash

— Waiter (uncredited)

Harry Schultz

— Aide (uncredited)

Slim Whitaker

— Crewman (uncredited)