Marine Centipede (1975)

Gomer lives in a humble fishing village where the men sail out to sea and the women stay behind to dive for sponge. The village has been troubled by a spate of disappearances on the part of its seafaring youngsters. Gomer learns of this upon returning from an extended voyage, and soon sets out in his tiny skiff to get to the bottom of things. Eventually he stumbles upon the island hideout of a band of modern day pirates who, under the leadership of a female captain named Odessa, are responsible for kidnapping and enslaving many of Gomer's friends and neighbors.