I'll update this with another, vaguely similar one: two days ago I watched another two movies from a "50 Classic Horror Movies" DVD boxed set I got for Christmas, and one of them was "Island of Lost Women".
It's almost as bad; a couple guys running from the police are marooned on an Island that is almost, but not entirely cut off from civilization; there is supposed to be a boat once a week. The women are pearl divers, and the boat comes to pick up the pearls, but otherwise they are isolated. The island is populated entirely by women and run by one particularly bad one. It's like a religious cult (heavily influenced by Hawaiian tradition; it was filmed in Hawaii).
The men are concerned about being captured by the police when the boat comes, and want to escape the island before then. One of the men gets "close to" one of the girls, and they plot to escape on an old boat they've found, and sail it to another island where they can hide until "the heat is off".
The old lady sees the two getting close, and condemns to girl to be sacrificed to a god, which amounts to being tied up and thrown to a shark... I won't bore you with the details; it's another stinker!

Just thought the titles were quite close.