And the Sea Will Tell (1991)

A wealthy couple James Brolin and Deidre Hall are killed on their yacht off the coast of a secluded South American island called Palmyra The suspects are a hippyish pair Hart Bochner and Rachel Ward whom the rich folks had befriended Its fairly clear that the hippies were involved in the crime The question is did the man do it while the girl looked on helplessly or was she a willing accomplice