Doug Standish, his assistant Dr. Craig Mosby, Dr. Phil Volker, Dr.
Maggie Hanford, Hank Stahl, and Dr. Orin Hillyard make up a team of
specialists in undersea life assembled for an expedition aboard the
Hydronaut, an atomic-powered submarine.
Their mission is to place electronic sensors at strategic places on
ocean beds throughout the world to provide an early-warning system
for the volcanic eruptions which have caused a worldwide series of
earthquake disasters. Orin Hillyard is injured when he tries to set
a sensor near an active volcano.
After finishing there job, the scientists head for the sunken treasure.
Just as they find it, they receive an urgent order by radio to place
one last sensor near a newly-discovered volcano; and they are forced
to abandon the treasure.
The volcano erupts as they are fixing the sensor, and the submarine
is trapped on the ocean bed by falling rock. Standish blows off half
of the ship with dynamite, with the result that the other half raises
safely to the surface. A helicopter comes to their rescue.
Lloyd Bridges - Dr. Doug Standish
Brian Kelly - Dr. Craig Mosby
Shirley Eaton - Dr. Margaret E. 'Maggie' Hanford
David McCallum - Dr. Philip Volker
Keenan Wynn - Hank Stahl Marshall Thompson - Dr. Orin Hillyard
Gary Merrill - Dr. August 'Gus' Boren
Ron Hayes - Brinkman
George Shibata - Prof. Uji Hamaru
Donald Linton - Vice President of the USA
Frank Logan - Captain of the Diligence
Don Wells - Sonar Man on the Dilligence
Jack Ewalt - Jack Smith
George De Vries - Coast Guard Lieutenant
Tony Gulliver - Officer
Joey Carter - Technician
Celeste Yarnall - Secretary
Paul Gray - Pilot