U-1302 was a Type VIIC/41, a slight modification of the workhorse Type VII U-boat that the Kriegsmarine had built by the hundreds. The /41 variant had a stronger pressure hull and could dive deeper — to about 230 metres — but in every other respect she was the same boat that had hunted the Atlantic convoys from 1939. She was launched at Flensburger Schiffbau in northern Germany and commissioned on 25 May 1944. By that point in the war, the U-boat campaign had effectively been defeated: long-range maritime patrol aircraft, escort carriers, the cracking of the Enigma cipher, and centimetric radar had together turned what had been the Atlantic's most feared predator into one of the most dangerous places to serve in any of the war's navies. Of approximately 40,000 men who served on U-boats during the war, around 28,000 were killed — a casualty rate of 70 percent. Crews knew the odds. They sailed anyway.

U-1302 spent her early months with the 4th U-boat Flotilla at Stettin for training, then transferred on 1 January 1945 to the 11th U-boat Flotilla at Bergen, Norway, for operational duty. Her first and only war patrol began in February 1945. She sailed for the western approaches and the St George's Channel — the narrow body of water between southern Ireland and the Welsh coast, where Allied shipping bound for Liverpool, Belfast, and Cardiff converged into predictable lanes. Between 28 February and 6 March 1945, Herwartz sank three Allied merchant ships there: the Norwegian SS Novasli, the Canadian SS King Edward, and the British SS Dovela. Forty-seven civilian sailors and crew died on those three ships. The pattern that had defined the entire Atlantic war — German submariners and Allied merchant crews killing each other in cold water — held to the end.

Escort Group 25 of the Royal Canadian Navy was a hunter-killer group operating out of Londonderry in the closing months of the war. Frigates of the River class — purpose-built anti-submarine ships, smaller and slower than fleet destroyers but better suited to the patient, methodical work of submarine hunting — made up the group's strength. On 7 March 1945, La Hulloise, Strathadam, and Thetford Mines worked together in a coordinated attack pattern that had taken five years of Atlantic war to refine: one frigate held the asdic contact and directed; the others ran in successively with patterns of depth charges. The hedgehog and squid mortars that newer frigates carried allowed forward-thrown salvos that did not require the hunter to pass over the target before attacking. The first attack at 14:28 produced an oil slick. Wreckage came up afterwards. There were no survivors.

The German wartime record for U-1302 lists forty-eight crew members lost on 7 March 1945. They were submariners, conscripts and volunteers, mostly men in their twenties — the youngest crew on Type VII boats by 1944 were often nineteen-year-old Funkmaaten (radio operators) and Maschinenmaaten (engine room hands). Their war had been short. Most had been at sea less than a year. None of them had grown up choosing the regime they fought for; many of them had grown up under it without knowing anything else. To say so is not to absolve the German state, which conscripted them into a criminal war, but to remember that the men who died inside U-1302 were not abstract numbers. They had mothers, brothers, fiancées. Their bodies are in the wreck. The wreck is on the bottom of the Irish Sea, where La Hulloise put it.

Karl Dönitz, the U-boat arm's commander and by then Hitler's nominal successor, signed the order ending submarine operations on 4 May 1945, two months and three days after U-1302 went down. By that point seven more U-boats had been sunk in British and Irish waters with all hands. The men of U-1302 were therefore among the very last of the U-boat campaign's dead, and their loss was not strategically significant in any way that mattered to the outcome of the war — the war was already over in any operational sense. What their deaths represented, instead, was the long tail of catastrophe that the Nazi regime had set running and could not stop, even when stopping would have saved the boys who served it. La Hulloise survived the war, was sold for civilian use in 1965, and was scrapped in 1968. The wreck of U-1302 has never been positively located.