Bigalk spent some years in the merchant marine before joining the Kriegsmarine in April 1934.

He initially trained as an observer in the naval air force, and saw service during the Spanish Civil War, making 21 combat flights in 1937.

[2] This included the 11,000 ton British escort carrier HMS Audacity from convoy HG 76, sunk on 21 December 1941 during his fourth patrol, for which Bigalk was awarded the Knight's Cross.

[1] Bigalk died on 17 July 1942 when U-751 was sunk with all hands by depth charges dropped by a Whitley bomber from No.

61 Squadron RAF in the North Atlantic north-west of Cape Ortegal, Spain.