[TorpX]

Mar. 5 _____ W12, 15, 10, pt cloudy ______ 75 mi.

Mar. 6 _____W10, 14, pt cloudy__________ 41 mi.

Mar. 7 _____W14, 15, 9, clear, hazy _______38 mi.

Mar. 8 _____W9, 12, hazy, overcast _______41 mi.
2349 we are about 8 nm off coast of Mindanao.

Mar. 9 _____W12, 15 __________________71 mi.
0313 plot course to mouth of Davao Gulf. We have been on patrol for 3 weeks now. Fuel 69%. 0800 sonar
malfunctions.. fixed by 1400. Bad time for this.

Mar. 10 _____W15 __________________ 33 mi.
From our present position, it is 2,900 nm to Fremantle, by way of Balikpapan. 1548 large a/c spotted. It is too
close, we dive to 160 ft. 1645 another a/c, unk type.
2320 plot course SW through Celebes Sea, speed 1/3, ~4 kn.
We can maybe patrol that area for a week, before supply issues force us to return. This is our 31st day at sea.

Mar. 11 ______W15, 5, 12 ______________86 mi.
We submerge and continue at 46 ft.

Mar. 12 ______W12, 5, 3 _____________95 mi.
We decide to transit on surface from here; speed from 4½ to 6 kn.

Mar. 13 ______W3, 0, 14, ____________ 116 mi.
1900 overcast, hv. rain. speed drops.

Mar. 14 ______W14, 8, 3, rain to pt. cloudy ____119 mi.

Mar. 15 ______W3, 7, _______________95 mi.
0000 enter Makassar St. patrol area. All stop. Fuel 62%.
We patrol submerged in day going across the strait.
0620 crew reports engines made funny sound before dive, but seem ok? We don't need any engine problems!

Mar. 16 ______W7, 0 _______________ 38 mi.

Mar. 17 ______W3, 0, 8 _____________49 mi.
0722 ship sighted! bearing 212°, long range. We are on course 137T. Ring up standard speed, course 260T.
0733 Sound GQ.
We are in a bad position, and must make a series of high speed sprints, then slow to take observations. We are losing bearing, so we must accept a longer shot than I would like. After 5 observations, we set gyros, and make ready all tubes.

Tracking Data Sheet:
time ___sub c/sp ___ Ms, Mt ___Tgt id ___ Range ___Aob ___ Bearing ____ Speed/ Course
0739 ___254T _____#1, #2 _____MR ____9850 yd.__70P ____084° ______
0744 __3 to 8 kn. ___ #3, #4 ____ _______8250 yd. __75 P ___082° ______9.5? course 222?
0750 __ _________#5, #6 __ Med. Eu.___ 6750 ____75 P ____078° _______C 212
0757 ____________#7, #8 __ composite __4950 ____70P ____073° ______S 11? C 210?
0803 ___________#9, #10____________3600 ____80P ____065° ______10 kn.

Set gyros at +40°, Track angle 133 P. (This gives a TTa of 93° P.)
Longitudinal spread.
Torpedo run estimated to be 2,900 yds. for a time of 2:27.
Launch on bearing 53.75°.

[The first points in line correspond to the last observation in the data sheet. After this point calculations are made and gyros are set.
The second points are the positions at torpedo launch.
The last points are the positions at impact.]

I planed to use all four torpedoes, but the last one is delayed and I check fire, as the target has moved too far along. 2:33 after launch, at 0809 hrs., the first one hits after the stack, the second hits near the stern. The third misses aft.
0816 target is burning, and seems to have lost propulsion.
0830 target appears to be slowly settling.
0834 target sinks.


Medium European composite freighter, 5,186 tons [0-56N, 119-20E]

0840 resume course 135T, secure from GQ.

I am very pleased with the tracking party; we were in a difficult position, but were able to calculate and execute an effective attack.
We were using full speed, which gave about 8.5 kn. This was necessary, but also required about a minute to slow to 4 kn. for a periscope observation. The average speed at this run was 7 knots. This, and the long range, precluded a larger number of observations.

The Academy could put this one in their book.