On 13 April 1940 during the battles around Narvik, Norway "U-46" was depth charged and severely damaged by British destroyers supporting . Sohler eventually commanded "U-46" for six war patrols, but failed to score any successes against enemy shipping. He was removed from command on 21 May 1940 and was replaced by Engelbert Endrass the following day. Endrass had been Günther Prien's First Officer aboard when they had infiltrated Scapa Flow and sunk the battleship . "U-46" was to be his first command.