TCM showed 1964's For Those Who Think Young today as part of a festival of teen-surf movies from the '60s. This was United Artists' entry in the genre, though while it has somewhat better production values than the Beach Party movies, it's a lot less fun, and somehow wastes what is, on paper, a pretty good cast; among the people in it are Pamela Tiffin, Ellen Burstyn, Paul Lynde, Bob Denver, and Tina Louise (the latter two both a year away from being stranded on that island together), but in this movie they have so little to do that you long for Frankie Avalon. Most of the material goes to "comedian" Woody Woodbury, while Paul Lynde mostly seems to be Woodbury's stooge -- not the best disposition of resources.
The most memorable part of the movie is the most horrifying; when I saw this on TV over a decade ago, I was completely disgusted and creeped out by this scene. For reasons I have never been able to figure out, Bob Denver is buried in the sand so that only his upside-down mouth is visible, and his disembodied, bearded mouth and painted chin proceed to lead a musical number.
Again, it makes you kind of appreciate the Beach Party franchise, where the numbers were silly, but at least they were fun rather than gross.
By the way, the musical director and composer for this movie was Jerry Fielding. Which means that Straw Dogs is not the most disturbing movie he scored.