Finding seals ie essentially a matter of operating in areas where experience has 
shown the most seale to congregate. The tsukimbo-sen which concentrated on fur seals 
rather than porpoises during the war years followed the fur seal migrations as previously 
delineated (pp 32-34), operating successively out of the ports nearest the best waters at 
each particular season (Figure 14). Their usual itinerary was about as follows: 
TABLE H. - APPROXIMATE SCHEDULE FOR SEALING OPERATIONS 
ae 
Uchiura-wan, Hokknido 
Off Chiba Prefecture 
Off Fukushima and Miyagi prefectures 
Off Iwate and Aomori prefectures 
From Aomori to Erimo~-zaki 







| December-earl¥ February 
Late February-early March 
Mid-March through April 
First half of May 
Last half of May 





Once in the predetermined area, the sealers pay strict attention to the water 
temperature, and until they find seals test it with a thermometer hourly or oftener. The 
optimum temperature is considered to be between 43°=45° (6°-79C) in February and March but 
increases in April and May to 479-529, The first Japanese investigators found this true 
in 1893 and 1894 (Bibl 57, 60, 65, 67, 72, 73, 74), and the seals apparently have not 
changed their preferences. During last epring's observatims 83 percent of the seals were 
encountered in watere within this optimum range, 16 percent in colder currents (41°F), and 
only 1 percent in warmer areas (47°F), Thus the vessel looking for seals tries to find 
and remain within water of the proper temperature, Otherwise, finding them is simply a 
matter of going where they have occurred before, or where other vessels in the vicinity 
report having seen them recently, 
Unless the sea is very calm the tsukimbo-asen enter harbor every night. This 
confines their operating area to within 50 miles of the coast, because their normal speed 
of 6 knots limits the day's run to about 100 miles. Hence most of their hunting is done 
from 10 to 40 miles off shore. They usually leave their harbor early enough in the morning 
to reach the hunting grounds by dawn, hunt as long as conditions remain favorable, and then 
return to shelter at night, although in periode of steady, calm, favorable weather they may 
remain at sea for two or three days at a time. 
Pelagic sealing is so difficult in rough weather that if the day is certain to be 
windy the ships usually remain in port. In addition to the physical discomfort of bouncing 
around on a 20-ton craft, shooting from the bow platform is almost impossible in heavy 
seas. Likewise, surface visibility is so limited in choppy waters that it is difficult to 
find the seals or to follow them when found. On calm daye, however, the seals frequently 
sleep quietly on the surface, and on an oily, slick sea are visible at some distance, 
especially when they hold up their hind-flippers with their mitten-like digits or turn on 
their sides and raise a blade-shaped fore-flipper straight upward, which they often do. 
A seal sleeping with flippers folded hes been described aptly as resembling a short charred 
log drifting on the sea (Figure 15). 
In the old days of hand-propelled hunting boats, sleeping seals were easily 
stalked and shot or harpooned before they waked, but a teukimbo-aen seldom gets within 
shooting range without rousing them. The throbbing of the noisy engines disturbs then at 
some distance, even when approached from leeward. They usually appear confused at first 
as to the source of the noise and raise their heads to look around the horizon in search 
of it. As seon as the intruder is located the animal dives and flees in the opposite 
direction. When pressed the seals may swim 50 to 100 yards under water, appearing only 
for an instant on the surface to snatch.a breath, often making little more than a swirl in 
the water. Or they may progress ina series of rapid, looping, porpoise-like dives, with 
the entire body clearing the water. Usually they flee straight away or at a tangent, but 
occasionally one doubles back, diving under the vessel «+d reappearing astern. As a seai's 
top speed of seven to eight mots can be maintained for only a short time, the tsukinbo- 
sen have little trouble in running them down, When the sea is emooth the seals can be 
42 
