 "U-718" was fitted with five torpedo tubes (four fitted at the bow and one at the stern), fourteen torpedoes, one SK C/35 naval gun, 220 rounds, and two twin C/30 anti-aircraft guns.The boat had a complement of between forty-four and sixty.On the 18 November 1943, "U-718" was conducting training as part of a "wolfpack" near Bornholm in the Baltic Sea under "Oberleutnant zur See" Helmut Wieduwilt, when she was accidentally rammed by .