While covering a test of guided torpedoes, two reporters believe they see what appears to be a strange-looking swimming creature. They investigate the matter further and discover that there is a race of fish-men living under the sea. The fish-men capture the pair and keep them prisoner in their underwater city.
as Ken Abe
as Jenny Gleason
as Commander Brown
as Dr. Moore
as Dr. Josef Heim
as Submarine captain
as Nishida
as Henchman
as Nakamura
as Female researcher
as Bill
as Captain Bob