 On 20 August 1944, in a Soviet air raid on the Romanian harbor of Constanţa in the Black Sea, "U-18" was damaged and as a result was deemed not seaworthy and was scuttled on the 25th.The boat was raised by the USSR in late 1944.It was sunk for target practice by the Soviet submarine on 26 May 1947 off Sevastopol (also sunk that day was the former ).