Ricardo Montalban
— Dr. Luis Delgado
José Ferrer
— Dr. Alfred Vreeland
Leslie Nielsen
— Official
Chris Robinson
— Ledring
Katherine Woodville
— Barbara Brand
Lawrence P. Casey
— Bob Exeter
Tom Simcox
— Jerry Hollis
Curt Lowens
— Ehrlich
Austin Stoker
— Bogan
Phil Philbin
— First Technician
Dan Chandler
— Sonar Man
Ted Swanson
— Aide
Myron Natwick
— First Reporter
Harlan Warde
— Second Reporter
Elisa Ingram
— Jean Hollis
Joan Murphy
— Norma
William Evenson
— Jim Morgan