An engineer, a psychologist and several other disparate types take part in an experiment to see if people can live for extended periods of time in a city built under the ocean.
William Lundigan
Bob Gage
Julie Adams
Dr. Monica Powers
Roy Roberts
Tim Graham
Carl Benton Reid
Dr. Junius Halstead
Chet Douglas
Chuck Marlow
Paul Dubov
George Burnett
Karen Norris
Phyllis Gatewood
Kathie Browne
Dotty Steele
Edward Mallory
Lt. Wally Steele
Edmund Cobb
Meade (uncredited)
George DeNormand
Dr. Carl Wendt (uncredited)
Paul Power
Author in Visiting Party (uncredited)
Ronald Stein
Original Music Composer
Gordon Avil
Director of Photography
Frank McDonald
Director
Orville H. Hampton
Writer
Al Clark
Editor
Alex Gordon
Producer
Donald W. Starling
Ben Lane
Makeup Artist
Howard Lydecker
Special Effects Coordinator
Story
Don Ament
Art Direction
Ruth Alexander
