Don Winslow of the Navy

Gang Radioman Barker

Saboteur Kramer [Chs. 3-4]

Enemy Sub Capt. Tranker [Ch. 1]

Spencer Merlin

Henchman Corley

Henchman Prindle

Native Henchman at Mill [Ch. 5]

Seaman Chapman

Witch Doctor Koloka [Chs. 6-7]

The CINCUS [Ch. 1]