The Bermuda Depths

In this 1978 fantasy film, a group of scientists are threatened by a beautiful girl who seems to have returned from the dead and a prehistoric sea creature that dwells in the deadly Bermuda Triangle. The woman, Jennie Haniver, is revealed to be an ancient legend come to life, with supernatural powers and a connection to the sea that drives her to make a terrible bargain for eternal life. As the story unfolds, a series of terrifying events ensues, culminating in a desperate battle between the surviving characters and the monstrous creature that haunts the ocean depths.