Flower-class corvette
This Allied advantage was offset by the growing numbers of U-boats coming into service. The Type VIIC began reaching the Atlantic in large numbers in 1941; by the end of 1945, 568 had been commissioned. Although the Allies could protect their convoys in late 1941, they were not sinking many U-boats. The Flower-class corvette escorts could detect and defend, but they were not fast enough to attack effectively.