Complex sentence: Following his voluntary transfer back to the "Kriegsmarine" in 1943 he took command of in 1944 which he took on one war patrol, during which he claimed to have sunk six ships for a total of and two corvettes.
Split into simpler sentences: Following his voluntary transfer back to the "Kriegsmarine" in 1943 he took command of in 1944 which he took on one war patrol. He claimed to have sunk six ships for a total of and two corvettes.