The most cost-effective British weapon of World War II: the Fairey Swordfish biplane piloted by Sub-Lieutenant John Moffat of 818 Naval Air Squadron launched from Ark Royal:
Günther Lütjens - Wikipedia, the free encyclopedia: A British reconnaissance aircraft sighted Bismarck in the early morning hours of 26 May by following its oil slick. At this point, the Home Fleet and Norfolk following from the north were joined by HMS Rodney, while Force H and light cruiser HMS Dorsetshire approached from the south, and light cruiser HMS Edinburgh from the west. Bismarck's low speed and southeasterly heading away from its known pursuers made it very easy for the new attackers to the south to catch up.
At dusk on 26 May, Swordfish torpedo aircraft from HMS Ark Royal attacked. Though much of the damage was superficial, one torpedo jammed Bismarck's rudders and steering gear, rendering it largely unmaneuverable. Divers were put over the side but reported they could not clear the damage as the sea was then too rough. The crew was still able to steer Bismarck somewhat by adjusting the revolution speed of her propellers, but it reduced the ship's top speed to 7 kn (13 km/h; 8.1 mph) and effectively left it circling in the water. Throughout the night she was the target of incessant torpedo attacks by HMS Cossack, Sikh, Maori, Zulu, and Piorun.
Lütjens recognised the gravity of the situation. At 23:58 on 26 May, Lütjens transmitted to Group West, the Naval HQ:
To the Führer of the German Reich, Adolf Hitler. We will fight to the last in our trust in you, my Führer, and our firm confidence in Germany's victory.