This was the most westerly point in the United Kingdom from where planes could patrol the Atlantic and offer some protection to the shipping convoys against the dreaded U-boats.

[citation needed] A meeting took place in January 1941 between Éamon de Valera and John Maffey, the British representative in Dublin.

[citation needed] To pacify the Germans, these aircraft were supposed to follow a defined route and then only on air/sea rescue missions.

The original agreement and rules were soon changed and the flying boats went on missions to the mid-Atlantic, to the west coast of France and to Iceland to protect convoys on those routes.

Some nine U-boats were confirmed as having been sunk by the Lough Erne Short Sunderland and Catalina flying boats and many others so badly damaged that they had to return to base in France.

209 Squadron RAF based at Lough Erne observed and pinpointed the battleship Bismarck in 1941, a stroke of tactical intelligence that helped lead to the warship's destruction.