For Those Who Think Young (1964)

About this title: In this beach movie, a group of teenagers hang out at the Silver Palms everyday after school. Because things can get quite raucous in the club, the protagonist's grandfather wants to shut it down. When the clever kids discover that grandpa used to be a bootlegger, they blackmail him into keeping it open. Sandra Brennan, All Movie Guide

Note: This is a general synopsis. Each listing is further described below.