U-235: Surrender with Strange Cargo In the final days of World War II, one German submarine was still running. U-234 departed Europe on a long-range mission to Japan carrying sealed cargo: jet technology, advanced weapons data, and uranium oxide. But as the submarine crossed the Atlantic, Nazi Germany collapsed. Orders became unclear. The war ended — while the mission continued. On May 14, 1945, U-234 surfaced and surrendered to the United States Navy. Its cargo vanished into secrecy, becoming o