Directed by Paul Wendkos. Poor Susan Dey. Her acting career just consisted of being abused. When she wasn't pretending to sing and play the Fender Rhodes on the "Partridge Family," she was thrown in prison in 1975's "Cage Without a Key" or in this movie terrorized by dune buggy-crazed beach thugs. And goodness knows throughout it all she didn't allow herself a square meal.
So yeah, this is essentially a biker movie without the bikes. The ruffians drive dune buggies, don't ask why. But the movie is less about Susan Dey unfortunately and more about her ineffectual goofy dad, played by Dennis Weaver, and how he eventually finds his center and stands up to these assholes in the last ten minutes of the flick. The other 80 minutes is pretty standard biker movie fare, where they bully the family and you wish something else would happen.
I'll say this -- great vehicles. I love these early '70s dune buggies and especially the tricked out camper van that the Dennis Weavers are driving around in. It's got the pop-top roof and the booth-style table. I love that stuff. Otherwise, I can't believe I sat through this.