'Seewolf' (iii) was a U-boat wolfpack operation in the Atlantic (14 April/1 May 1945).
The wolfpack comprised U-518, U-546, U-805, U-858, U-880 and U-1235, and for the loss of Oberleutnant Hans-Werner Offermann’s U-518, Kapitänleutnant Paul Just’s U-546, Kapitänleutnant Gerhard Schötzau’s U-880 and Kapitänleutnant Franz Barsch’s U-1235 sank only the US destroyer escort Frederick C. Davis.
This was the only attempt at a wolfpack operation in Atlantic waters with Schnorchel-equipped boats. Grossadmiral Karl Dönitz, who was still in day-to-day control of the U-boat arm via Konteradmiral Eberhard Godt, the service’s operations chief, despite the fact that he was commander-in-chief of the German navy, established the 'Seewolf' (iii) wolfpack in the North Atlantic on 14 April with the object of combing the Great Circle route for convoys moving in a westward direction. The German deployment movement was detected by 'Ultra', and 'Teardrop' was organised to tackle the wolfpack. Two carrier groups established search lines north of the Azores islands group on what is known to be the U-boats' course to counter what was initially believed to be a German attempt to bombard the USA’s eastern seaboard with V-2 ballistic missiles launched from towed containers.
In the north was Captain J. R. Ruhsenberger’s Task Group 22.2 (escort carrier Mission Bay and destroyer escorts Douglas L. Howard, J. R. Y. Blakely, Hill, Fessenden, Farquhar, Pride, Menges and Mosley), and in the south Captain Craig’s TG22.5 (escort carrier Croatan and destroyer escorts Frost, Huse, Inch, Stanton, Swasey, Carter, Neal A. Scott, Muir and Sutton).
Despite adverse weather, warships of TG22.5 located U-1235 and U-880 on sonar during 15 and 16 April, and Stanton and Frost sank both the boats with salvoes of 'Hedgehog' bombs. U-805 was sighted by an aeroplane operating from Azores islands group, but escaped two long searches.
On 22 April Carter and Neal A. Scott of TG22.5 sank U-518 before another two carrier groups arrived to relieve the first two: in the north was now Captain Robert S. Purvis’s TG22.4 (escort carrier Core and destroyer escorts Moore, Sloat, Tomich and J. Richard Ward), and in the south Captain George J. Dufek’s TG22.3 (escort carrier Bogue and destroyer escorts Haverfield, Willis, Wilhoite and Swenning). Forward of these was TG22.7 as a search line with the destroyer escorts Pillsbury, Keith, Otterstetter, Pope, Flaherty, Chatelain, Frederick C. Davis, Neunzer, Joseph C. Hubbard, Varian, Otter, Hayter, Janssen and Cockrill.
On 24 April one of Bogue's aircraft sighted and reported U-546, which was then hunted by Neunzer, Chatelain, Varian, Janssen, Joseph C. Hubbard, Pillsbury and Keith. Even so, the boat was able to sink Frederick C. Davis with a single straight-running torpedo. After a hunt of almost six hours, however, U-546 was driven to the surface, just missed Flaherty with a torpedo and then sank.
U-858 and U-805 managed to reach the US coast, as did U-853 and U-530 sailing independently, and U-889 and U-881 followed on behind these four. In attempting to attack the task group based on the escort carrier Mission Bay, which had again set out after replenishing, the last was sunk on 6 May by Farquhar. U-853 probably sank the submarine chaser Eagle 56 on 23 April and, after sinking the 5,353-ton collier Black Point, was itself sunk on 5 May by the patrol frigate Moberly, destroyer Ericsson and destroyer escorts Atherton and Amick.