Germany: U-boats claimed 14.4 million tons, but Germany lost 821 U-boats (see Map of Lost U-Boats). Allied aircraft were responsible for (or directly involved in) the loss of 433 U-boats; surface ships, 252; accidents, 45; mines, 34; submarines 25 (only one of which happened when both hunter and victim were submerged); unknown, 15; scuttled by their own crews, 14; interned in neutral ports, 2; sunk by shore battery, 1.
comes from "Hitlers Lost Sub" site
Just adding my 2cents.............
