About 40 miles off the coast of Poland, nearly 300 feet below the surface of the Baltic Sea, a beam of light cut through the cold water and fell onto the metal hulk of a ship. As the light panned across the wreck in September 2020, it cast long shadows across the seafloor. For the first time in 75 years, the Nazi-era steamship Karlsruhe had been seen by human eyes.“It is one of the last unresolved mysteries of the Second World War,” says Tomasz Stachura, the president of the SANTI…
