Five Desperate Women is a 1971 American TV film directed by Ted Post.
He makes his way to a private beach, drowns a man relaxing on the shore, and steals his work uniform.
Five young women reunite, they are having their 5-year college reunion at an exclusive cottage on an isolated island that does not have phone contact with the mainland.
The four women lock the men out of the cottage and agree to not leave each other alone for the rest of the night.
The other women wander the beach while waiting, and come across information that proves Wylie, the man they have come to trust, is the actual killer.
Her friends, after at first being fearful of getting too close to the attack, are able to save her by knocking Wylie over the head with a rock, which kills him.