Dived in position 27 miles north of Amami and proceeded westward submerged to patrol area about midway between Amami and Tokay Gunto.
0910 Inter sighted Arusehi Juna and Takara Jima.
0945 Inter sighted ??koate Shima. The above islands rise high above water and make excellent navigational land marks.
0950 Inter sighted smoke and masts of steamer in position Latitude 29º-05''N, Longitude 129º-34'E, course 200ºT. Commenced approach. Upon reducing range steamer was seen to be small coal burning coastal steamer estimated 1500 tons. Speed was estimated by plot to be ?.5 knots. Decided not disclose presence the first day in this area by attacking such a small target. Broke off approach at 5000 yards. Steamer was obviously headed for Naze Ko.
All navigational lights on Amami O Shima were blacked out and no lights could be seen on shore.
2316 Inter sighted steamer, range about 8000 yards, estimated course 020º. We were about 20º on his port bow. Moonlight with overcast sky gave good visibility. Dived for periscope attack. Ran in on 90º track. Target picked up through periscope at about 5000 yards and recognized to be a freighter of about 5000 tons.
2340 Inter attack #2, Latitude 28º-37'N longitude 129º-10'E, fired longitudinal spread of four torpedos. Two explosions heard 35 seconds after firing. Ship settled immediately by the bow.
2354 Inter ship was observed to sink through periscope.
2356 Inter surfaced and cleared area to westward.