The Bermuda Depths is a Japanese/American co-production 1978 fantasy film originally broadcast as a made-for-TV movie written by Arthur Rankin Jr. of Rankin/Bass fame.

Special effects and creature elements were handled by Tsuburaya Productions, most famous for the Ultraman franchise.

On a Bermuda beach, a sleeping Magnus Dens is approached by a beautiful but mysterious woman, Jennie Haniver, who seems to recognize him.

In the meantime, Magnus is dreaming of his childhood, playing on the same beach, watching a turtle egg hatch with his friend Jennie.

The scene then shifts to young Magnus on the beach spotting Jennie riding the turtle, heading out to open sea and disappearing beneath the water as he calls after her, then shifts again to his nightmare of the night his father, Lionel, was knocked into the water by an unseen horror in the cave beneath the house and part of his house on a cliff crumbling down to the beach as the storm rages on.

Finally awakening and groggily gathering his things to go to town, Magnus sees a woman swimming in the ocean.

Dr Paulis tells him the woman must have been joking with him, as "Jennie Haniver" is the name given to a sea creature of local folklore.

Paulis explains that Lionel was conducting tests regarding mutation in sea life when he was attacked and apparently eaten.

Magnus climbs aboard the lifeboat amidst the wreckage and desperately tries to help Eric on board, but he is entangled in the line from the Horror.

The turtle surfaces, its eyes glowing green exactly like Jennie's, before it dives down into the depths, dragging Eric helplessly behind.

Jennie approaches an unconscious Magnus lying face flat on the beach, sadly kisses him, then returns to the ocean for the last time.

Doshan approaches Magnus in the graveyard where his parents are buried and expresses her horror at the losses of her husband and Dr. Paulis.

It sinks past the giant turtle, which is shown to have the same initials Magnus inscribed on its shell all those many years ago.