AllMovie

A carefree cruise on a luxurious yacht descends into a deadly love triangle in Ruggero Deodato's take on Roman Polanski's Knife in the Water. Invited on a weekend cruise by wealthy industrialist Giorgio and his pretty wife Silvia, free-spirited young couple Irem (Al Cliver) and Barbara (Silvia Dionisio) look forward to a leisurely few days at sea. Once out on the water, however, Irem and Barbara make some disturbing discoveries about their outwardly amiable hosts: Giorgio is an abusive cynic who dominates his wife with a heavy hand, and neurotic Silvia submits to her tyrannical husband's every depraved demand. Later, when Sylvia seduces their naïve guests into striking back at Giorgio, the betrayal sends the ruthless captain into a murderous rage.