A not dissimilar project, but this time between two points. While this scene is a little busier than the swimmer the river seems to be sufficiently isolating to make the point, as it were.
In the first image, the white and blue boat is clearly the most dominant point due to its size and position in the foreground; it's difficult even to see what the other point/boat is in the distance. There is a sense though that one is following the other, set up within the context of the river providing a narrowish space in which the action would be expected to take place. In the second image the last boat, which it is now possible to see is an orange lifeboat, is the more dominant, mostly because of its colour this time although it is of course also closer to the foreground. It still feels as if it's very much following in the wake of the first boat though, emphasising that sense of direction.