Tuesday,
25 May 1943 - South of the Cape Verde Islands
- 3rd week at sea completed -
0035 - Qu.1271ES - SSW6/5, medium swell, partly cloudy, medium visibility, >1000mb, shifting East.
0308 - Qu.1512ES - East6/5, medium swell, partly cloudy, medium visibility, >1000mb.
0700 - Qu.1557ES - Diving for torpedo maintenance and trial dive.
0707 - T=50. Beginning torpedo maintenance.
0758 - Tube I serviced.
0815 - Tube II pulled - Watch Change at 0811 -
0849 - Tube II serviced.
0940 - Tube III serviced (tubes I-III are T-3/Pi39H).
1031 - Tube V serviced (EtoFat/Pi39H).
1042 - Sunrise.
1122 - Tube VI serviced (T-4/Pi39H).
1130 - Reception Depth. Beginning of Trial Dive acc.
B.d.U. Standing Order No.507 & No.308. 145rpm/3kn.
1150 - CO₂ Warning at 1.7% (after 4h 50min.).
1200 - Qu.1584ES -
Days Run: 152.5nm - ↗ 133.2nm (16h 50') - ↘ 19.3nm (7h 10')
Total: 3827.3nm (20tg 22h) - ↗ 3666.9nm (18tg 12h 04') - ↘ 160.4nm (2tg 9h 56')
458cbm (3cbm in 24h); Course 161°; T=A+50; Battery 63%; CO₂ 1.8%; 3xT-3, 2xEtoFat, 1xT-4; 9xBold.
1216 - Boat is safe and secure at 2A-Meter. Setting for T=20 with 145rpm.
1227 - At A-Meter, 96rpm.
1231 - Boat rises to T=18.5m.
1234 - Boat is level at Reception Depth (140m in 18min. at 145rpm and 96rpm). Battery 61.5%; Compressed Air Supply 285 Atü; CO₂ 1.8%.
1239 -
F.T. from B.d.U.:
To all U-boat Commanders:
1) Our heavy U-boat losses in the last month are to be attributed primarily to the present superiority of enemy location gear and the surprise attacks from the air enabled by these. More than half of these losses have occurred by reason of their surprise tactics, on approach and return passage, as well as in the operational area in attack positions. The losses in attacks against convoys themselves were, however, slight except for one case in which conditions were particularly unfavorable. A part of these losses also occurred through air attack.
2) The present situation in regard to enemy aircraft and enemy location must be counterbalanced, through entailing other disadvantages, by special precautionary measures while proceeding and in waiting positions. Orders regarding this have been issued. I shall also come to further conclusions in the selection of operational area.
3) I am directing my whole attention to the improvement of our own location, anti-location means and Flak armament. This problem is being worked on everywhere with great concentration. Practical results will shortly be introduced for operations. Until then cruising and waiting must be carried out with skill and care, but actual attacks with the same tenacity as ever.
- signed - B.d.U. & Grand Admiral Karl Dönitz -
1240 - Surfaced after 40min. and 2.2nm since Etmal (Total: 5h 40min. and 15.7nm). Weather and Sea unchanged in 9.5h.
1242 - Boat ventilated and Compressed Air Supply filled. 2x225RPM/8kn.
1611 - SE1/1, partly cloudy, light haze, medium visibility, >1000mb.
1615 - Charging batteries (61.5%): Stbd.-Charging, 496RPM; Port-Propulsion, 285RPM/8kn.
1930 - Batteries charged => 3h 15min. for 38.5%. 2xSmall-Ahead/185RPM/7kn
1935 - Test Run of main diesels acc.
B.d.U.-Standing Order No.510. - 285RPM/1/3-Ahead/10kn.
1940 - 375RPM/2xH.F./13kn.
1945 - 455RPM/Full-Ahead/16kn.
1950 - 496RPM/A.K./18kn/30min.
2020 - Reducing speed in speed settings of 5min. decrements.
2035 - 2x225RPM/8kn.
2311 - Sundown. Weather and Sea unchanged since 1611 (7h).