730 
BULLETIN OF THE BUREAU OF FISHERIES 
Although the first Diesel-powered vessel on Puget Sound, the cannery tender 
Warrior, which was built in 1914 at Seattle by Nilson and Kelez (Pacific Fisherman 
Yearbook for 1919), was successful in operation and very economical, the original 
cost of these engines was too great to encourage their ready acceptance. However, 
during the years of expansion of the fleet following 1925, the many advantages of 
Diesel engines encouraged their installation in a majority of the new vessels. In 
recent years there have been no further radical changes in type or design of purse-seine 
vessels. 
Increase in Vessel Size 
Improvements in vessel design were accompanied by a parallel increase in vessel 
size. It is impossible to determine the exact size of all vessels in the fleets of early 
years, since most of them were of less than 5 net tons and were not required to be 
officially registered. We may obtain some indication of the increase in vessel size, 
however, from records of the vessels large enough to be registered. The average 
size of vessels of this class, built in 1906, was only 6 net tons. That of 1907 was 
7.5 net tons, that of 1908 was 8.92 net tons, that of 1909 was 9.43 net tons, and that 
of 1910 was 9.97 net tons. 
This tendency to build larger vessels received great impetus with the beginning 
of the high-seas fishery at Cape Flattery and on Swiftsure Bank, where there were 
frequent storms, few harbors, and no protection. Practically no seiners had fished 
there prior to 1911, but the development of this fishery was very rapid. Several 
vessels were laid down during 1911 of more than 10 net tons, and in 1912 nearly 50 
vessels of 15-25 net tons were constructed. The size of vessels has continued to 
increase since that time. 
EVALUATION OF FISHING INTENSITY 
SEASONAL FLUCTUATIONS IN FLEET SIZE 
Factors Affecting Seasonal Intensity 
Variations in number of licenses in odd- and even-numbered years, and the 
licensing of an additional amount of gear in the fall of the year, have been noted in 
the discussion of scow seines. The operation of these factors was intensified by the 
conversion of the purse-seine fleet to power vessels and by the increase in vessel size 
which followed. 
The larger seine vessels were now able to run from their home ports on Puget 
Sound to southeastern Alaska with little difficulty, and some even voyaged as far as 
Bristol Bay. The termination of the fishing season in Alaska usually occurred early 
enough to allow them to return to Puget Sound and fish during the coho and chum 
runs in the fall. 
Since about 1925 the development of Alaskan herring-reduction plants attracted 
a fleet of large, able seine boats which fished from June to August or September, and 
many of which then returned to the Sound to further swell the fall fleet. Other large 
seiners, which fished in the California sardine fleets during the winter months, often 
fished in this region later in the year. During seasons when heavy runs of salmon 
were anticipated, certain vessels from the halibut fleet, which were constructed with 
a low stern suitable for seining, also engaged in the purse-seine fishery. 
