Critical Convoy Battles of WWII - Crisis in the North Atlantic, March 1943, Jurgen Rohwer.

Critical Convoy Battles of WWII - Crisis in the North Atlantic, March 1943, Jurgen Rohwer. 
Focuses on the successful U-boat attacks on convoys HX.229 and SC.122, looking at how earlier convoys were able to avoid attack, why those particular convoys were hit so hard, the methods being used by both sides, and their impact on the longer term result of the Battle of the Atlantic. A useful study, despite its age (first published in 1977), in particular because of its focus on the successful German attacks of March 1943, which thus get the attention they deserve rather than being seen as a precursor to the Allied victories later in the summer.
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