 On July 19, 1942, he ordered the last boats to withdraw from the United States Atlantic coast; by the end of July 1942 he had shifted his attention back to the North Atlantic.Convoy SC 94 marked the return of the U-boats to the convoys from Canada to Britain.The command centre for the submarines operating in the West, including the Atlantic also changed, moving to a newly constructed command bunker at the Château de Pignerolle just east of Angers on the Loire river.