Friday,
28 May 1943 - Southwest of Freetown
0258 - Qu.8756ES - NW7/6, overcast, rain, poor visibility, <1000mb - Running off on course 90°.
0300 - Diving due to poor visibility. Submerged cruise at Reception Depth.
0755 - Qu.8765ES - CO₂ Warning at 1.7%.
1057 - S-Tiefe. It has cleared up but there is still a medium swell. CO₂ is 2.2%.
1100 - Surfaced after 20.9nm and 8h.
NNW7/6, medium swell, clear, light haze, medium visibility, >1000mb.
1101 - Boat ventilated. 2x225RPM/8kn.
1200 - Qu.8844ES -
Days Run: 120.5nm - ↗ 94.4nm (14h) - ↘ 26.1nm (10')
Total: 4342.8nm (23tg 22h) - ↗ 4154.1nm (21tg 01h 24') - ↘ 188.7nm (2tg 20h 36')
450.5cbm (1.5cbm in 24h); Battery 80%; Course 90°; 3xT-3, 2xEtoFat, 1xT-4; 9xBold
NE7/6, medium swell, clear, light haze, medium visibility, >1000mb
1215 -
Outgoing F.T.:
To B.d.U.:
Supply boat not found. 450cbm. NE7/6, medium swell, clear, light haze, medium visibility, >1000mb. Moving off to the East. - RST -
1230 - Qu.8845ES - Course 180°.
1320 - Qu.8848ES - Course 270°. Heading back to the supply area.
1729 - Qu.8759ES - E7/6, medium swell, clear, light haze, medium visibility, >1000mb - Course 340°.
1834 - Course 270°. No sight of supply boat.
2118 - Qu.8746ES - NE7/6, medium swell, clear, light haze, medium visibility, >1000mb.
2307 -
Incoming Radio Reports:
From O.K.W.:
a) Yesterday, fourteen Mosquito bombers from RAF Marham, conducted a daylight raid on the Zeiss optical instrument plant at Jena, some 45 miles from Leipzig. Despite losing three aircraft over the target and two others written off whilst attempting to land on their return, the operation had caused some damage to the works.
b) The 15th US Airforce attacked the Oil Refineries in Livorno, Italy.
From. B.d.U.:
B.d.U.-Standing Order No. 42 from 27 May 1943:
a) Only a plot drawn up accurately with every report on the enemy and the enemy route marked in enables one to find a convoy quickly and operate successfully against it.
b) The first night of operations always promises the best chance of success. Therefore, try to fire as quickly as possible when the convoy is reached.
c) On moonlight nights the enemy appears to protect primarily the side away from the moon. Attacks from the moon side, therefore, are more likely to be successful in many cases, also in view of less danger of location.
d) Always try to escape on the surface from locating escort vessels, since the enemy usually breaks off the chase quickly and cannot leave the convoy for too long.
e) Try to ward off escort aircraft if possible at once, if Flak guns are ready for action, but above all before dark in order not to lose valuable chances of attack.
f) Only submerge in view of aircraft if the boat can with certainty reach at least 80-100 m. If there is any doubt remain surfaced and ward off attack. Train the crew for this and keep in mind the danger of being bombed at low diving depth.
g) Make every effort to eliminate the possibilities of surprise attacks while underway and in position. Either proceed with main engine running, in order to hear aircraft beforehand, or submerge in unfavorable weather conditions.
h) In some cases decoy depth charges were again dropped with great success. Do not be deceived by these but go to periscope depth as quickly as possible, if there are no hydrophone fixes, and investigate.
j) If the convoy frequency is very busy use alternative wave lengths.
2315 - Sundown. Weather and Sea unchanged in 2h.