Despite some dodgy camera-work (rapid zooms and shots thrown in and out of focus), a few plodding moments and some dated looking scenes involving 'groovy' teenagers, Mario Bava's A Bay of Blood is still an entertaining slasher/giallo movie, made even more notable by the fact that it heavily influenced Sean S. Cunningham's 80s classic, Friday the 13th, made almost a decade later. The waterside setting, randy teenagers, inventive bloody murders, vengeful son, and surprise ending were all elements borrowed from Bava's movie; all Cunningham had to do was dumb down the story a tad and he had one of the most successful horror movies of all time!<br /><br />In Bava's movie, a wealthy elderly woman is killed by her husband, who has been talked into committing the murder by his daughter and her greedy spouse, who wish to inherit and develop the titular bay. The murderous husband is then killed immediately after, by an unseen assailant. As the film progresses, more and more people are killed in gory fashion, until Bava reveals that there are several killers responsible and each has their own reason for committing the murders. The film ends with a ridiculous twist, which makes one wonder whether Bava was having a bit of a laugh at the audience's expense.<br /><br />Filling his movie with plenty of bloody mayhem and nudity, Bava establishes the slasher formula that would prove successful for so many imitators. The bloody death scenes include throat slashings, hangings, strangulation, and impalements to keep gore-hounds happy, whilst those who appreciate a bit of T&A with their horror will be more than happy with a gratuitous skinny dipping scene featuring a full frontal from Brigitte Skay.<br /><br />Since A Bay of Blood has so much going for it, it is a shame that it tends to drag in places and has many dark scenes in which it is hard to see what is happening. However, this is such an 'important' movie that I do urge any self-respecting horror fan to see it, if only to witness the film that initiated a whole sub-genre—the slasher.<br /><br />If IMDb allowed it, I would award A Bay of Blood a rating of six and a half out of ten—since I cannot do this, I will round my score up to a respectable seven.