The Neptune Factor

The Neptune Factor is a 1973 science fiction film directed by Daniel Petrie, featuring underwater cinematography by Paul Herbermann. The films special effects utilized underwater photography of miniatures with actual marine life.

The nature of the Oceanlab underwater facility bears a resemblance to realworld projects of the 1960s such as the ConShelf Two project of Jacques Cousteau, NASAs NEEMO, and the US Navy SEALAB.

Source: Wikipedia