A girl who lives in a small seaside town is caught having sex. As punishment She is sent to a boarding school.
There she makes friends with girls who sneak out and socialize with men. It turns out that the men are actually making adult films.
The girl is talked into being in a film but at the last minute they are busted by the police. (I remember this taking place on a boat)
It turns out the headmistress of the school is involved in suppling girls for the films. The girl returns to her seaside home.
I would have seen this on television in the ’90s.