From Polanski’s breath-taking cinematography, we can immediately recall the young hitchhiker leaning over the edge of the sailboat and cutting through the water – the simplicity and profundity of that action.  Why this title then? What are the implications of it, and how does it refer to things that may or may not be salient to us in the film? Regardless, the title conjures up something, of the impotence of the otherwise deadly knife when it seeks to penetrate the water which only yields to it, makes a space for it, and then simply returns to its original state, unperturbed. It also conjures up a sense of unseen danger: a knife unseen in the depths of the water.  And all of this we can see very subtly and unobtrusively coming to us in Polanski’s unassuming masterpiece, A Knife in the Water.

The image of a knife blade cutting through the water can be likened to the image Polanski presents to us of the young hitchhiker cutting his fingers through the water while the three characters are on the sailboat.  His fingers, the knife, cut through the water, displacing the water on either side. But once this foreign element is removed, the water comes back together bearing no scar of this temporary forced entry.  In much the same way, this young boy parts the married couple for the time that he is on the sailboat, displacing them for a day, before they come back together once more and this foreign element is removed from their lives.

Later, however, in the early morning confrontation between the boy and the husband, the husband throws the knife at the boy who fumbles with it before it finally falls into the water.   The knife has disappeared into the water, to remain there forever, virtually impossible the remove.  In the same way, even after the boy leaves, he remains, like the knife, in the water as an unseen threat to their marriage. In the end, it is a catch-22 for the husband. Either he must believe that the boy is dead and remain with that guilt and feeling a criminal before his wife, or he must accept the boy’s survival and believe that she has cheated on him. Either way, the boy’s presence in their lives will be permanent, though unseen, like the knife lying somewhere in the depths of the water.

Between the boy and the husband, the knife takes on a special significance.  The boy is masterful with the knife, and risks maiming himself by playing a game where he rapidly jabs the knife in between each of his fingers. The knife then seems to represent a youthful adventurousness and fearlessness, even a recklessness. It seems to symbolise vitality and passion – all that, as his wife reveals later in the film, the husband had when he was younger but which he has lost as he become more conventional and successful.  In effect, the older man is fighting the boy in order to prove to all three of them that he has not grown soft in his old age with a more sterile life.  As such, it is a power play when the husband commandeers the boy’s knife, and in the boy’s attempts to recover it, the knife is thrown overboard.   Both men have lost the knife, and perhaps we are led to believe that this may prove a rite of passage for the boy. Will he, after leaving them, give up some of his young, wild ways and begin an evolution which may end in a person resembling the husband?

This film is simple and provocative. One can simply enjoy it for its brilliant cinematography and understated grace, or think more carefully about what it reveals about relationships and human development (and political significance?).  Either way, it is a joy to watch.