'Seewolf' (ii) was a U-boat wolfpack operation in the Atlantic against the SC.123 and HX.230 convoys (21/30 March 1943).

Based on an initial eight boats which concentrated to form the pack on 21 March, and joined by another seven boats after that time, the wolfpack eventually comprised U-84, U-86, U-257, U-305, U-333, U-336, U-373, U-440, U-441, U-527, U-530, U-590, U-591, U-615, U-618, U-631 , U-641, U-642 and U-666, and neither lost any of its own number nor sank any ship.