The Bermuda Depths is a 1978 horror movie that manages to combine Giant Monsters and Supernatural Romance. It was coproduced by Rankin Bass and Tsuburaya Productions of Ultraman fame.
A drifter named Magnus (Leigh McCloskey) returns to his home in Bermuda (which he left after his father was mysteriously killed years before) and is reunited with Eric (Carl Weathers), an old friend who is learning about marine biology from an old scientist named Dr. Paulus. They end up investigating evidence of a giant turtle inhabiting the local waters.
Magnus also meets a mysterious, beautiful woman named Jennie Haniver (Connie Sellecca), who turns out to have been a childhood playmate of his; in fact, he’s still wearing the seashell necklace she gave him. The thing is, she only appears when he’s alone, and even Eric tells Magnus that they believed Jennie was just an Imaginary Friend of his. He insists that she was real, and that he even carved his and Jennie’s initials on the back of a turtle they played with.
Eric’s wife explains that Jennie Haniver is a local Urban Legend: Two hundred years ago, a young woman whose ship sank in a storm in the Bermuda Triangle made a Deal with the Devil so that she would survive. Naturally Magnus refuses to believe it is the same Jennie.
Eric becomes obsessed with catching the giant turtle and against all warnings uses a harpoon cannon on it. This just leads to the creature killing him and Dr. Paulus. Jennie is revealed as indeed being supernatural in the process.
Tropes in The Bermuda Depths:
- Bermuda Triangle: One of the oddest takes on the legend: The reason for all of the disappearances there? It was a giant turtle demon.
- Boy Meets Ghoul: It is never exactly clear what Jennie was—ghost, cursed immortal, etc.—or why she first appeared to Magnus as a little girl.
- The Drifter: Magnus is from Bermuda, but left his home and went on to walk the Earth before the events of the film, before returning home at the start of the film.
- Dying Deal Upgrade: One young zoology student meets a charming young woman named Jennie Haniver. Doctor Paulis, the veteran oceanologist, recounts the myth of Jennie Haniver: she was a bride betrothed to wealthy merchant across the sea. When the ship ferrying Jennie to her groom started to sink during a fierce storm, Jennie prayed to the Devil to spare her life. Her prayer was answered: she became an immortal mermaid, cursed forever to lure able sailors to their doom. The zoology student subsequently drowns.
- Eaten Alive: Magnus' father is revealed to have died after being eaten alive by the turtle demon, apparently for finding evidence that the turtle demon existed.
- Hoist by His Own Petard: Eric dies yanked underwater by the harpoon line.
- Who Wants to Live Forever?: Jennie came to regret her pact but cannot escape it.
