Don Terry
Cmdr. Don Winslow
Acting
Claire Dodd
Mercedes Colby
Acting
John Litel
Spencer Merlin
Acting
Walter Sande
Lt. Red Pennington
Acting
Anne Nagel
Misty Gaye
Acting
Wade Boteler
Mike Splendor
Acting
Ben Taggart
John Blake
Acting
John Holland
Paul Barsac
Acting
Lane Chandler
Henchman Corley
Acting
Ethan Laidlaw
Henchman Spike
Acting
Peter Leeds
Seaman Chapman
Acting
Robert Barron
Henchman Prindle
Acting
Kurt Katch
The Scorpion
Acting
Ray Teal
Gang Radioman Barker
Acting
Dirk Thane
Lt. Cdr. Grady
Acting
Herbert Rawlinson
Admiral Warburton [Ch. 1]
Acting
Samuel S. Hinds
The CINCUS [Ch. 1]
Acting
Kenneth Harlan
Capt. Holding [Ch. 1]
Acting
Arthur Loft
Enemy Sub Capt. Tranker [Ch. 1]
Acting
Paul Scott
Capt. Fairfield, of the "Batavia" [Chs. 1-2]
Acting
Jerry Mandy
Tangita Jim [Chs. 2, 10]
Acting
Heenan Elliott
Capt. Sanders, of the "Tarleton" [Chs. 3-4]
Acting
Paul Bryar
Saboteur Kramer [Chs. 3-4]
Acting
Edward Hearn
Lead Henchman at Mill [Ch. 5]
Acting
Iron Eyes Cody
Native Henchman at Mill [Ch. 5]
Acting
Frank Lackteen
Witch Doctor Koloka [Chs. 6-7]
Acting
Guy Kingsford
Sub Capt. Jackson [Chs. 7, 9]
Acting
Ken Terrell
Sam Munn, henchman [Ch. 8]
Acting
Jack Rockwell
Henchman Butch [Ch. 8]
Acting
Irving Mitchell
Gang Chemist Taylor [Chs. 8-9]
Acting
Eddie Polo
Taylor's Lab Assistant [Ch. 8]
Acting