Donitz Wolfpack

Rudeltaktik, the coordinated U-boat group tactic devised by Karl Donitz, then Befehlshaber der U-Boote in the Kriegsmarine. Boats patrolled a search line, the first to sight a convoy shadowed it and radioed BdU headquarters, which vectored the pack in for a massed night surface attack to swamp the escort. The tactic dominated the Battle of the Atlantic through 1942 and peaked in early 1943. It broke in May 1943 (“Black May”), when 41 U-boats were lost to escort groups, escort carriers, HF/DF, and centimetric radar.