Ernest Borgnine in The Neptune Factor (1973)

Set in the north Atlantic, off Nova Scotia, deep deep beneath the ocean waves, Director Dr. Andrews (Walter Pidgeon) is trying to keep his Project Neptune team's oceanographic research going aboard the OceanLab II, a sea base located near a dark abyss, in spite of opposition from Foundation Head, Dr. Norton Shepherd (Ed McGibbon). On the ocean floor, a small team of scientists led by Dr. Hal Hamilton (Michael J. Reynolds) prepare to leave their underwater laboratory, about to return to the surface, after an extended stay performing research on undersea earthquakes. Ironically, a huge underwater earthquake interrupts the Marine scientists' plans. The undersea lab they are all living in gets hits by an earthquake, which rips the lab loose from its moorings, and the cracked sea floor sends their lab careening down the underwater mountain it was built on, and plummeting into the abyss, taking the team with it, who only have seven days of air. Trapped too deep for divers, the only chan