Bikini Beach (1964)

This film was the sequel to Beach Party (1963), but the previous film focused on its older stars, Bob Cummings and Dorothy Lamour.  Bikini Beach turns the focus on totally on the college kids and their antics.
A publishing millionaire named Honeywagon (Keenan Wynn) sets out to prove the college kids, led by Frankie and Dee Dee (Frankie Avalon, Annette Funicello), have no more intelligence than his pet ape Clyde (Janos Prohaska). This upsets Vivian (Martha Hyer), a colleague of Honeywagon's who thinks the kids are being treated unfairly.

A British pop star named Potato Bug (also played by Avalon) sets up tents on the beach, and makes the girls go wild, which doesn't go over with the guys too well.  In addition, the kids have to once again deal with Eric Von Zipper (Harvey Lembeck) and his motorcycle gang.

This is one of the better "beach movies", in that it goes at a fast, breezy pace.  None of the beach movies will ever be thought of as great art, but several of them were a fun way to pass ninety minutes.  Don Rickles is featured as the owner of a race car garage and the dance club where the kids hang out.  Stevie Wonder sings a song, and Boris Karloff has a cameo.