Waves of Lust is probably best described as a lurid, erotic, titillation thriller. Ruggero Deodato directs his then squeeze, the always lovely Silvia Dionisio, who co-stars to strip off every ten minutes to placate the audience for the more unsatisfying thriller elements of the script. John Steiner turns in a marvellous sadistic performance as the controlling wealthy industrialist husband of Elizabeth Turner, who pairs up with Al Cliver and Silvia Dionisio respectively for a weekend of nookie and wife swapping on his yacht. With Steiner's character becoming more paranoid and delusional as the film progresses, events take a dangerous turn for the worse in the third act. But, the conclusion feels rushed to the point of annoyance.
The 80's Australian blockbuster Dead Calm bears a strong resemblance to this in some regards and explored these themes more successfully. But, Steiner's performance, the persistently naked presence of Dionisio and some nice cinematography by Mario Capriotti raise this from the doldrums.
Lamberto Bava gets an early co-screenwriting credit here and Deodato's and Dionisio's son Saverio gets a cameo near the start of the film.