U-553 under Karl Thurmann August 1942 Bahamas patrol

Korvettenkapitän Karl Thurmann, a veteran on the boat’s eighth patrol out of ten, arrived next, transiting inwards on the 12th of August and passing south of Turks & Caicos on the 15th and 16th. This placed his Type VIIC boat U-553 in the Windward Passage on the 17th, and enabled Thurmann to sink the Blankaholm(Swedish, 2,845 tons) and the John Hancock (American, 7,176 tons) and damage the Empire Beede (British, 6,959 tons) at the doorstep of Guantanamo Bay on the 18th of August.
Following these successes the submarine was itself attacked by HMS Pimpernel and kept on the defensive. The Pimpernel eventually sank the Empire Beede as a hazard to navigation (Wynn, Vol. 2, p.31).  On a patrol to and from Saint Nazaire for the Third Flotilla, U-552 spent a total of nine patrol days in the area, and re-entered on the 26th of August via the Mona Passage. From there the boat headed due east over the north coast of Puerto Rico and east of Anegada on the 28th.
Interestingly, on the way to the patrol area via the northern route off Newfoundland, U-553 damaged the Belgian Soldier, of 7,167 tons. The harrowing tale of this ship’s rescue in the North Atlantic is ably told by raconteur Farley Mowat in Gray Seas Under. This patrol began on the 19th of July in Saint Nazaire. U-553 participated in the pursuit of convoy ON 115 off Greenland and the Pirat patrol line. This resulted in the sinking of the British Lochkatrineeast of St. John’s Newfoundland on the 3rd of August. The patrol ended on the 17th of September, 1942 in Saint Nazaire.
A member of the Crew of 1928, Thurmann worked his way up from Seekadett (cadet) serving on light cruisers Emden and Köln to Korvettenkapitän in August 1942 – the promotion was awarded during this patrol. The same month, also during the patrol, he was awarded the Knights Cross. Judging from the account of Teddy Suhren receiving an award while on patrol, there would have been some kind of ceremony on board to celebrate this high honor – when conditions permitted of course (U-boat War Patrol – The Hidden Photographic Diary of U-564, by Lawrence Paterson).
Thurmann joined U-boats in April 1940 and he commissioned U-553 three days before Christmas the same year. Thurmann would live until January 20, 1943 – he was 30 at the time of his patrol. His total tonnage was 61,390 tons sunk plus a warship of 925 tons destroyed and two ships damaged for 15,273 tons. His final patrol began on the 16th of January 1943 from La Pallice, France. A week later his enigmatic final radio message was “periscope not clear” from the mid-Atlantic. The submarine and its 47 crew were never heard from again.

SOURCES: Gudmundur Helgason, Rainer Kolbicz, www.uboat.net, 2011, Kenneth Wynn, U-boat Operations of the Second World War, Volume 1 and Volume 2, 1997, Lawrence Paterson, U-boat War Patrol – The Hidden Photographic Diary of U-564, 2004