Marlon Brando as Robert Crain

Yul Brynner as Captain Müller

Janet Margolin as Esther

Trevor Howard as Colonel Statter

Martin Benrath as Kruse

Hans Christian Blech as Donkeyman

Wally Cox as Dr. Ambach

Max Haufler as Branner

Rainer Penkert as Milkereit

William Redfield as Baldwin

Oscar Beregi Jr. as Admiral (as Oscar Beregi)

Martin Brandt as Nissen

Charles De Vries as Kurz

Carl Esmond as Busch

Martin Kosleck as Wilke

Norbert Schiller as Steward

Rick Traeger as Schultz

Ivan Triesault as Lt. Brandt

Robert Sorrells as Koeniger

Eric Braeden as Radio Officer (uncredited)

Frank London as Merchant Marine (uncredited)

Jim Goodwin as Merchant Marine (uncredited)

Gregg Barton as Merchant Marine (uncredited)

Paul Baxley as Crew Member (uncredited)

Hal Bokar as Merchant Marine (uncredited)

Heinz Brinkmann as Crew Member (uncredited)

Gene Dynarski as Merchant Marine (uncredited)

Harold Dyrenforth as Cornelson, Ingo Navigator (uncredited)

Horst Ebersberg as Crew Member (uncredited)

Fritz Ford as Crew Member (uncredited)

Harold Goodwin as Merchant Marine (uncredited)

Sam Javis as Merchant Marine (uncredited)

Roy Jenson as Merchant Marine (uncredited)

Buck Kartalian as Merchant Marine (uncredited)

Robert Kino as Capt. Hatsuma (uncredited)

Manfred Lating as Lutz (uncredited)