Gene Evans
Steve Karnes
Acting
André Morell
Prof. James Bickford
Acting
Leigh Madison
Jean Trevethan
Acting
John Turner
John
Acting
Alastair Hunter
Dr. C. A. Morris, the village doctor
Acting
Lloyd Lamble
Senior Admiral, at the Admiralty
Acting
Jack MacGowran
Dr. Sampson, the paleontologist
Acting
Maurice Kaufmann
Mini Submarine Officer
Acting
Henri Vidon
Tom Trevethan
Acting
Patrick Jordan
Photo Lab Aide
Acting
Howard Lang
Naval Commader, at the "Valkyrie" wreck (uncredited)
Acting
Leonard Sachs
Dialogue Scientist at Conference (bit)
Acting
Ernest Blyth
Scientist at Conference (uncredited)
Acting
Neal Arden
TV Newscaster (uncredited)
Acting
Paul Beradi
Man Listening to Car Radio (uncredited)
Acting
Max Faulkner
PLA Radio Operator (uncredited)
Acting
Neil Hallett
Dr. Sampson's Helicopter Pilot (uncredited)
Acting
André Maranne
French Radio Officer (uncredited)
Acting
Derren Nesbitt
The Radar Operator, at the radar room (uncredited)
Acting
Guy Standeven
Naval Officer in Situation Room (uncredited)
Acting