In the World War II, in order to support the war from sea, Germany who was in war with Russia, decided to establish a sea fleet in the Black Sea. After the neutral side Turkey closed the straits, Germans bring their ships to Romania by boats from Elbe and Tuna rivers and by trucks from the roads. The sea fleet established in the Kostence harbour was a lot of attack boats, mine cleaner ships and six submarines in his structure. The submarines fighted against the Russian Fleet in the Black Sea. But the land wars turned against the Germans. Red army, captured Romania in August 1944 and sunked the three of the submarines in the Kostence harbour. The other three which managed to escape from the harbour was stucked in the Black sea after Russia captured Bulgaria. Without any other chances the captains of the submarines decided to sunk their submarines near the Turkish Coast. Their plan was to reach the Aegean islands and somehow to reach Germany from there. In the night of 10 th and 11th of september 1944 the submarines have been sunked by their crew near Eregli. But unfortunately after a few days in Turkiye they were caught and kept heldive in Beysehir and Isparta for two years.
She is now in 41.16N , 31.26E coordinates. In other sources her position was mentioned as 41°11'N-30°02'E and 41.11N, 30.00E. But her exact location is still unknown.
Books that mention this submarine:
German U-Boat Losses During World War II, Niestle, Axel, 1998
Letzter Befehl: Versenken, Arendt, Rudolf, 1998
Okrety plyna po ladzie, Piwowoñski, Jan, 1959
U-Boat Adventures, Wiggins, Melanie, 1999
U-Boat Operations of the Second World War - Vol 1, Wynn, Kenneth, 1998
U-Boat Operations of the Second World War - Vol 2, Wynn, Kenneth, 1998
U-23 Submarine's detailed operation list.
U-23 Submarine's crew list.
Ships sunked by u-23:
04 October 1939 : S.S. "Glen Farg" (876 tons)
05 December 1939 : S.S. "Scotia" (2400 tons)
11 January 1940 : S.S. "Fredville" (1150 tons)
12 January 1940 : S.S. "Danmark" (10517 tons)
24 January 1940 : S.S. "Bisp" (1000 tons)
14 February 1940 : S.S. "Tiberton" (5225 tons)
18 February 1940 : H.M.S. "Daring" (1375 tons)
22 February 1940 : S.S. "Loch Maddy" (4996 tons)
24 August 1943 : TSC-578
15 October 1943 : TSC-486
17 October 1943 : S.S. "Achilleon"
23 October 1943 : M.V. "Tanais" (372 tons)
23 October 1943 : S.S. "Sovetskaja Rossya"
05 April 1944 : SKA-099 (chasseur de Sous-Marins)
07 April 1944 : V 187.4/Rion barge soviet
29 May 1944 : S.S. "Smelyij" petrolier
01 September 1944 : S.S. "Oituz" (2686 tons)