Full Cast & Crew

George O'Brien as Cmdr. Robert 'Bob' Kingsley

Marion Lessing as Anna Marie Von Steuben

Mona Maris as Fraulein Lolita

Walter C. Kelly as Chief Mike 'Guns' Costello

Warren Hymer as 'Lug' Kaufman

Steve Pendleton as Ens. Richard 'Dick' Cabot (as Gaylord Pendleton)

Walter McGrail as Chief Joe Cobb

Larry Kent as Lt. 'Mac' McGregor

Henry Victor as Baron Ernst von Steuben (U-boat commander)

John Loder as Franz Shiller

Philip Ahlm as German Chief Petty Officer (uncredited)

Al Bennett as Naval Reservist (uncredited)

Earl Wayland Bowman as Naval Reservist/Swimmer and Diver (uncredited)

Bill Brande as Naval Reservist (uncredited)

William Collier Sr. as Mugs O'Flaherty (uncredited)

Leonard Davison as Naval Reservist (uncredited)

Joseph Depew as Naval Reservist (uncredited)

Francis Ford as Eric - Captain of Trawler (uncredited)

Robert Ford as Naval Reservist (uncredited)

Hans Fuerberg as Fritz Kampf (Second Officer of U-172) (uncredited)

Curt Furberg as Hoffman (uncredited)

Al Generaux as Naval Reservist (uncredited)

Bob Gillette as Naval Reservist (uncredited)

George Golden as Naval Reservist (uncredited)

Ben Hall as Elmer Harrigan (uncredited)

George Harris as Naval Reservist/Swimmer and Diver (uncredited)

Bob Kyle as Naval Reservist (uncredited)

Jack Martin as Naval Reservist (uncredited)

Harry Mount as Bugler on Gun Crew (uncredited)

Jack Murphy as Naval Reservist (uncredited)

Maurice Murphy as Merkel (uncredited)

Bob Nelson as Naval Reservist (uncredited)

Edward Peil Jr. as Naval Reservist (uncredited)

Nat Pendleton as 'Butch' Wagner (uncredited)

Terrance Ray as 'Skits' Reilly (uncredited)

Marvin Schecter as Gunner (uncredited)

Harry Schultz as German Officer (uncredited)

Ferdinand Schumann-Heink as Adolph Brucker (uncredited)

Robert Shepherd as Naval Reservist (uncredited)

Harry Strang as Gunner and drill sergeant (uncredited)

Anton Tell as German Chief Petty Officer (uncredited)

George Templeton as Naval Reservist (uncredited)

Harry Tenbrook as Winkler (uncredited)

T.J.F. von Blankerburg as Naval Reservist/Swimmer and Diver (uncredited)

Frank Walton as Naval Reservist/Swimmer and Diver (uncredited)

Harry Weil as Levinsky (uncredited)

Hans Winterhalder as German Chief Petty Officer (uncredited)