WW2 RN Black Signal Flag 'U-Boat Hunting' - Liverpool 1943

Symbolising death this black flag was manufactured and stamped by Porter Bros of Liverpool , 1943 and measures 25 x 17'. The black flag was raised when Royal Navy warships identified a located a German U-Boat and began hunting it. Liverpool was the headquarter for the Western Approaches and one of the main ports where convoys would depart and arrive.