At sixty days the next patrol, led by KapitänleutnantFreidrich Markworth in U-66 qualifies as the longest single enemy patrol in the Bahamas area during either war. It began where it ended – one third of the way from Bermuda to Anegada, on the 29th of May 1943 and would last just shy of two months – to the 25th of July at almost exactly the same spot. In that time the boat, on its eighth of nine patrols, with a Knights Cross holder at the periscope patrolled northwest for five days until it arrived off the Savannah-Georgia-to-Jacksonville-Florida cruising ground, where it was to remain for the better part of six weeks.
From 31 May to 21 July the boat crisscrossed the Gulf Stream where it stretched from the American mainland east 100 to 150 miles, back and forth repetitively looking for prey. On the 10th of June U-66’s torpedoes found and sank the large US tanker Esso Gettysburg, setting the naval establishment as well as the tanker alight. The loss of life from the inferno (fifty-seven men were killed) was sobering to all who were made aware of it. Roughly three weeks later Markworth found the similarly large US tanker Bloody Marsh (10,195 GRT) in the same general area southeast of Savannah and northeast of Jacksonville, and sent her to the bottom on the 2nd of July 1943.
Nearing the end of its precious fuel supply the boat turned slowly homeward, striking off to the southeast and past the exit for the Northeast Providence Channel before encountering the US tanker Cherry Valley, which put up a valiant fight on the 22nd of July roughly 300 miles east of San Salvador and escaped without being sunk. Having begun its patrol in Lorient on the 27th of April, U-66 was able to refuel from U-847 on the 19thof August 1943. She returned to base on the 1st of September.
After this lively battle U-66 turned east and made its way back to Lorient, crossing its inbound track and exiting the area south of Bermuda on the 25th of July. To have attacked three large American tankers and sunk two of them in highly contested waters and with the Banana River, Florida Naval Air Station so close was surely an impressive accomplishment.
U-66 was a highly successful U-boat, with thirty-three ships sunk worth an astounding 200,021 GRT plus another two damaged for 22,674 and two warships damaged for sixty-four tons. She would be sunk west of the Cape Verde Island by depth-charges, ramming and gunfire from aircraft flying off the USS Block Island and the US destroyer USS Buckley on 6 May, 1944 – thirty-six of her crew survived.
Kapitänluetnant Friedrich Markworth of the Crew of 1934 amassed an impressive tally during his career: thirteen ships sunk for 74,067 tons, the Cherry Valleydamaged, and two warships damaged as well. During this patrol – in fact barely a week after sinking the Bloody Marsh– Markworth was awarded the Knights Cross on the 8th of July. He joined U-boats from cruisers in July 1940 and served as First Watch Officer (1WO) on U-103. Korvettenkapitän Richard Zapp had led U-66 before Markworth took over.
On Markworth’s first patrol to the southern Caribbean he sank nine ships for 48,896 tons and mined Castries, Saint Lucia. On the way back from the patrol, however, whilst refueling from U-117 Markworth was so severely wounded by aircraft from USS Card that he relinquished command to Paul Frerks. U-117 was sunk. In October 1943 Markworth moved ashore to the 23rd (training) Flotilla, on the eve of defeat switching to the 25th Flotilla. Gerhard Seehausen assumed command of U-66 until her destruction some months later. Having served 325 patrol days on three missions, Markworth would go on to live until age 78, passing away in 1994.
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