The daily reports by 22 Danish seiners of the fish-meal fleet in the Bering Sea during the entire season of 1963 showed that the boats varied greatly with respect to both the average of daily catch yielded and the average of the number of daily hauls conducted. And the catcher list added such information that they also varied greatly with respect to both the principal particulars and the attached instruments. The probable relation of the daily catch or the daily hauls to either of these characters was examined. And the following results are obtained:
1. The boats with more powerful engines were inclined to yield better catches.
2. Four of the boats, which fished from different port and were equipped with different type of echo-sounder, yielded poorer catch than the others, although they did similar amount of work.
3. They were less powerful in the main engine than the other boats. It is, therefore, hard to tell whether the difference of the boat in the type of echo-sounder and in the home port directly resulted in the difference of the catch or was effective indirectly through the difference of the home port in the common views on the desirable power of the main engine of the boat.