The British Experiment That Accidentally Created a New Way to Hunt U-Boats

It is 4 November 1943, and the Atlantic convoy HX.264 cuts through heavy seas some eight hundred kilometres west of Ireland. The night is moonless, the water grey-black and violent, and amongst the forty-three merchant vessels steaming in formation, the men know they are being hunted. A British escort destroyer, HMS Sharpshooter, cuts through the water at the convoy's flank, her bridge awash with spray, her asdic operator hunched over a glowing screen below deck. What they are about to experience will change the entire character of the Battle of the Atlantic. Beneath the convoy, a German Type VIIC U-boat, the U-264, maintains station at a distance. Her captain has waited patiently. He has done this before—stalked these plodding merchant ships across the grey expanse, chosen his moment, and struck. But today he does not know that his torpedoes carry something new, something that none of his superiors in Berlin fully understand. As the attack begins, as the first acoustic homing torpedo leaves the tube and races through the water with one singular purpose, the British escort will experience a horror they have never encountered before. The weapon is not aiming for the merchant vessels. It is hunting the warship itself.