On 19 April 1943 a German submarine somewhere in the Mediterranean sent a routine radio message and then went silent. She was never heard from again. No enemy ship claimed her, no wreck was found, no survivor came home to explain. U-602 had left the harbour at Toulon eight days earlier and sailed off the edge of the record, taking every man aboard with her into an ending nobody has ever been able to fill in.
U-602 was a Type VIIC, the most heavily built submarine design in history and the backbone of Germany's war at sea. She was laid down at the Blohm & Voss yard in Hamburg early in 1941, launched that October, and commissioned four days after Christmas under Oberleutnant zur See Philipp Schüler. At about sixty-seven metres long, with a crew that ran between forty-four and sixty men, she was a cramped steel tube built to disappear beneath the waves and surface again where she was least expected. There was nothing exceptional about her; she was one of hundreds of near-identical boats rolling out of the German yards. That very ordinariness is part of why her disappearance left so faint a trace.
Her career followed a familiar arc. After working up with the 5th U-boat Flotilla, she went operational in the autumn of 1942 and joined the wolfpacks prowling the Atlantic convoy routes, among them a hunting group code-named Puma in October. Then she was ordered through the Strait of Gibraltar into the Mediterranean, a passage that killed many U-boats outright, and assigned to the 29th Flotilla for the rest of her service. The inland sea was a trap as much as a hunting ground: the only way in ran beneath British guns and aircraft at Gibraltar, and the only way out ran back beneath them. In four patrols U-602 was credited with sinking a single warship of about 1,540 tons. It was little to show for the risks her crew ran every day they were at sea.
In the spring of 1943 she sailed from the great French naval base at Toulon, on 11 April. Her last radio message came on 19 April. After that, nothing. For years the histories recorded that a British Hudson of No. 500 Squadron had sunk her four days later, on 23 April, but that attack was eventually traced to a different submarine, and it had done no damage at all. So the tidy entry in the loss ledger dissolved, and U-602 was left where she remains today: missing, cause unknown. A mine, a diving accident, a failure at depth, an attack no aircrew ever logged, any of these could have taken her, and the sea has never given up the answer. Somewhere on the Mediterranean floor lies a boat, and inside it the men who were still aboard when she stopped answering.
U-602 is not alone in that ambiguity. A striking number of U-boats are listed simply as lost to unknown causes, swallowed by a sea that keeps its secrets, and their crews are remembered by the coldest word in any war record: missing. For the families waiting in Germany there was no wreck to visit, no date they could be certain of, no account of a last stand, only a boat that failed to return and a silence that never lifted. She had a captain with a name, a crew of ordinary men, a home port, and a number. What she does not have, to this day, is an ending.
Plotted at 36.83°N, 0.00°, on the prime meridian in the open western Mediterranean, this point sits far from any coast, in the kind of empty blue water where U-602 spent her last patrol. From altitude there is only sea to every horizon, the Spanish Levante a distant smudge to the northwest and the Balearic Islands off to the northeast. Nearest airfields are Región de Murcia (LEMI), Alicante–Elche (LEAL), and, farther north, Valencia (LEVC). The water here runs deep and visibility is usually good, but there is nothing to see: this is a marker over a mystery, not a wreck anyone can point to.