This thriller has the unusual setting of a cross channel swim.Derek Bond,as was often the case plays a nasty two timing rat who gets in too deep with one of the swimmers and decides that the only way out of the situation is to murder her during her cross channel swim and to concoct an elaborate alibi. The police trey it as a simple case of drowning.However when Bond realises that her co swimmer Sheldon Lawrence suspects murder he decides to try and drown Lawrence.However all his plans come unstuck. Interesting to see in a garage scene Arthur Lowe and future director John Schlesinger. Although slightly predictable,entertaining to watch.