Prominent scientists Dr. William Beebe and Otis Barton, using the Bathyspere invented by Barton, descend several thousand feet to the ocean floor off of the shores of Bermuda to study and film sea creatures seen and filmed at that depth for the first time. A sometimes staged semi-documentary that was often sold and advertised as an exploitation/horror picture.
| Actor | Role |
|---|---|
| WWilliam BeebeDr. William Beebe | Dr. William Beebe |
| OOtis BartonOtis Barton | Otis Barton |
| JJohn Tee VanJohn Tee Van - Crew Member | John Tee Van - Crew Member |
| GGloria HollisterGloria Hollister - Crew Member | Gloria Hollister - Crew Member |
 Lowell ThomasNarrator | Narrator |