From aerial photographies taken on the 5th July 1972 at Tokyo Bay, the distribution of ships at anchor had been observed. The ship's lengths and seperation distances between each other are measured. Let own ship's lengths be L_0, the nearest other ship's lengths be L_1, and let the seperation distances between them be R_1, Fig.3 is drawn. And, let the secondly nearest ship's lengths be L_2, and the seperation distances to them be R_2, Fig.4 is drawn. The ratio R^^^_2/R^^^_1 is calculated to be almost 1.16. In Fig.6, from each ship an arrow is drawn to the nearest ship. And we can see that the group is composed of several clusters. Some ships receive multiple arrows, and it is found that the ship which receive multiple arrows is comparatively smaller than others. This fact suggests a hypothesis that smaller ship comes later to the centre of previously constructed distribution.
