The poster art for "The Witch Who Came from the Sea"--which is reproduced in gorgeous color, but frustratingly cropped form, on the cover of the DVD--has absolutely nothing to do with the movie itself. "Witch" is not a horror film, but rather a scathing indictment of child sexual abuse which occasionally veers into horror-like territory.
Millie Perkins plays Molly, a spacy barmaid who idolizes men on TV, dotes on her two young nephews, and often recalls her late, seafaring father with unnatural reverence. She also has ugly castration fantasies that she acts upon about fifteen minutes into the film(don't worry, I'm not giving away the movie's major revelation here). Perkins is really good in this role, and Lonny Chapman also gives a fine performance as her grizzled boyfriend.
What else works in this film? The dreary, battered Venice Beach and Santa Monica location shots. The creepy soundtrack. Molly's sad, uncomfortable, frightening flashbacks to childhood. What DOESN'T work is the dialogue. Robert Thom(Perkins' husband at the time) wrote in the Ernest Hemingway-Rod Serling style; everyone in the film speaks exactly the same way, and they all sound so nutty that you'll often be left scratching your head in frustration. I think that Thom was going for a folksy, man-and-woman-on-the-street feel(for 1976), but the language comes off as goofy and stilted. That said, watch the film anyway--it really is worth it. You'll never, ever forget "Witch". (Without giving anything away, the final scene is wonderful, almost perfect.)
Extras include commentary by Perkins, director Matt Cimber, and cinematographer Dean Cundey; interviews with the same; and trailers for some other movies. What's really interesting about the film itself is that there are two or three scenes which I never saw on the ancient VHS print I used to rent. Brace yourself before you see this; obviously the film is not suitable for children, but many adults will find it extraordinarily unpleasant as well.