This picture illustrates the problem:
I can cont
I think another approch would be:
Quote wikipedia:
In mathematics, a Voronoi diagram is a way of dividing space into a number of regions. A set of points (called seeds, sites, or generators) is specified beforehand and for each seed there will be a corresponding region consisting of all points closer to that seed than to any other.
So, you choose a target, follow it's path for some steps and set a seed point there. Do this with all other targets as well and you get a voroni diagram. Depending in which area you are, you move to the seedpoint of it. Viola, you got the first fish. Now repeat this step until you cought them all.