USS Blackfish (SS-221), a Gato-class submarine in commission from 1942 to 1946, was the only ship of the United States Navy to be named for the blackfish. During World War II, she completed five war patrols in the Atlantic Ocean between October 1942 and July 1943 in waters extending from Dakar, Senegal, to the north of Iceland. She supported the Allied invasion of French North Africa in Operation Torch in November 1942, and is credited with sinking the German vorpostenboot V 408 Haltenbank off the north coast of Spain in February 1943.

Vorpostenboot, also referred to as VP-Boats, flakships or outpost boats, were German patrol boats which served during both World Wars. They were used around coastal areas and in coastal operations, and were tasked with – among other things – coastal patrol, ship escort, and naval combat.