Trailer
Images
 | Gene Evans as Steve Karnes |
 | André Morell as Prof. James Bickford |
 | Leigh Madison as Jean Trevethan |
 | John Turner as John |
 | Alastair Hunter as Dr. C. A. Morris, the village doctor |
 | Lloyd Lamble as Senior Admiral, at the Admiralty |
 | Jack MacGowran as Dr. Sampson, the paleontologist |
 | Maurice Kaufmann as Mini Submarine Officer |
 | Henri Vidon as Tom Trevethan |
 | Patrick Jordan as Photo Lab Aide |
 | Howard Lang as Naval Commader, at the "Valkyrie" wreck (uncredited) |
 | Leonard Sachs as Dialogue Scientist at Conference (bit) |
| Ernest Blyth as Scientist at Conference (uncredited) |
| Neal Arden as TV Newscaster (uncredited) |
| Paul Beradi as Man Listening to Car Radio (uncredited) |
 | Max Faulkner as PLA Radio Operator (uncredited) |
 | Neil Hallett as Dr. Sampson's Helicopter Pilot (uncredited) |
 | André Maranne as French Radio Officer (uncredited) |
 | Derren Nesbitt as The Radar Operator, at the radar room (uncredited) |
 | Guy Standeven as Naval Officer in Situation Room (uncredited) |
| Writing | |
| Robert Abel | Story |
| Alan J. Adler | Story |
Directing | |
| Eugène Lourié | Director |
Writing | |
| Eugène Lourié | Screenplay |
Art | |
| Harry White | Art Direction |
| Eugène Lourié | Production Design |
Sound | |
| Edwin Astley | Original Music Composer |
Production | |
| David Diamond | Producer |
| Ted Lloyd | Producer |
Camera | |
| Ken Hodges | Director of Photography |
Editing | |
| Lee Doig | Editor |
Crew | |
| Jack Rabin | Special Effects |
Camera | |
| Desmond Davis | Camera Operator |
Crew | |
| Pete Peterson | Special Effects |
| Louis DeWitt | Special Effects |
Sound | |
| Richard Marden | Sound Editor |
Costume & Make-Up | |
| Jimmy Evans | Makeup Artist |
Crew | |
| Irving Block | Special Effects |
| Willis H. O'Brien | Special Effects |
Costume & Make-Up | |
| Bernadette Ibbetson | Hairstylist |
Directing | |
| Kim Mills | First Assistant Director |
Sound | |
| Edwin Astley | Conductor |
| Sid Wiles | Sound |
Directing | |
| Jennifer Herrinshaw | Continuity |
Production | |
| Jacques de Lane Lea | Production Manager |
Costume & Make-Up | |
| Freda Gibson | Wardrobe Master |
Visual Effects | |
| Willis H. O'Brien | Visual Effects |
Directing | |
| Douglas Hickox | Director |
Writing | |
| Daniel James | Screenplay |
