the early monoplanes. The defencive armament was extraordinary for the time when most military flying boats still used manual World War One Scarf ring mounts for single or twin rifle calibre machines guns in open positions. On long cold over-water flights, it was common for military flying boats to fly with canvas covers across the open gun positions because the gunners had difficulty in surviving the long hours of patrol at their posts. Some, such as the equally famous and successful Catalina had just two machineguns, one in each of two blister observation posts, where the blisters had to be opened to fire the guns. Having one four gun tail turret, a two gun mid-upper turret, and one two gun nose turret gave the Sunderland formidable fire power at all times. As a flying boat, the Sunderland could protect its belly by flying at very low level so that a fighter could not fly under it. This earned the German nick-name of 'Flying Porcupine' because it was considered a very dangerous target for a fighter to attack. The reputation was so strong that a Sunderland, on a ferry flight with no guns fitted to its turrets, was attacked by a Bf 110 twin engine heavy fighter armed with canon and machine guns but frightened the German aircraft off when a crew member fired a Thomson sub-machine gun, firing .45 ACP pistol bullets, at the German aircraft from one of the turrets. The Sunderland was also able to carry an effective