The Allies develop new ways to counter and destroy the U-Boat threat so that the Atlantic Ocean can continue to serve as the pipeline to victory in Europe, a crucial element to Allied success on D-Day. American, Canadian, and British air bases strategically placed along the Atlantic force U-Boats to stay submerged longer, which make them easy targets when they surface. The Allies produced new long range plans and converted merchant ships into smaller flat tops in order to reach the entirety of the Atlantic, limiting previous submarine “safe zones”. The USS Guadalcanal, which is one of the converted aircraft carriers, captured the U-Boat "U-505", the first enemy ship captured on the high seas since the War of 1812.