As of right now in my early career and as a relative newbie to SHIII, this most recent successful attack on a British convoy. Two ships sunk, waiting for a third. The Empire Class Freighter I hit exploded and sunk in less than three minutes. Should be almost 22-23K tons if it continues to go as planned... amazingly still not detected on this beautiful blue-bird day off the west coast of Ireland.
Moving at 1 knot and heading for 100m. Wish me luck!