U-518 next patrolled the region, entering midway Bermuda-Anegada on the 16th of September 1943 and proceeding due west for Abaco and Eleuthera. On the 24th of September U-518 entered the Northeast Providence Channel, and a day later rounded the Great Isaacs Light southbound into the US Gulf by rounding Key West westbound on the 29th. The boat, under Friedrich-Wilhelm Wissmann on its first of several patrols to the region, returned via Key West on the 14th of October, roughly two weeks later.
Steaming up the Gulf Stream for the next few days, it rounded West End Grand Bahama on the 16th and was in the open North Atlantic by the following day. Continuing northeast until the 19th to a point roughly a third of the way between Savannah and Bermuda, the boat then turned southeast and motored until the 24th of October. At that point it turned due east and exited the area at the same position it had arrived, on the 26th of October. On this 106-day patrol out of Lorient and into Bordeaux for the Second Flotilla, U-518 neither attacked nor sank any ships. The patrol lasted from 18th August to 1 December 1943.
Kapitänleutnant Wissmann was a member of the Crew of 1935. After serving in minesweepers he was First Watch Officer on U-109 under Heinrich Bleichrodt. Over four patrols of 304 days he sank eight ships for 52,346 tons and damaged two others for 15,440 GRT. Wissmann was selected for the secret mission to land a special agent on the North American mainland in 1942. Not only did U-518 succeed in the mission, landing a saboteur in Chaleur Bay Canada on the 9th of November 1942, but Wissmann managed to sink four ships and damage two in the vicinity as well. Not decorated during the war, he lived until the age of 47, passing in 1963.
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