On its 5th patrol in the Black Sea, the NMS Dolphin's orders were to cut the Russian supply routes for Sevastopol. The patrol lasted from 2–7 November 1941. Its commanding officer (CO) was Constantin Costăchescu. It was his 3rd patrol as the CO of the Dolphin (from the first 5 patrols of the Dolphin, Constantin Costăchescu was the CO for the 1st, 3rd and 5th). On the morning of 5 November at 08:05, sub lieutenant Constantin Stegaru spotted a big transport ship steaming for Yalta. At 08:43, Costăchescu launched one aft tube torpedo from 800 metres (2,625 ft) away. In a couple of moments, the torpedo explosion followed by another bigger one could be heard. It is possible that the ship was not escorted, because the first contact with the Soviet submarine-hunter ships took place after an hour. The anti submarine attack lasted from 10:30 until 18:30 and there were 80 to 90 depth charge explosions. The sunken Soviet ship was the 1,975-ton cargo Uralets (also known as Uralles).
Costăchescu was awarded the Order of Michael the Brave 3rd class. Romanian historians identified the Russian ship as being the Uralles, 1975-tonne cargo boat, but Soviet archives state that the Uralles was sunk by Luftwaffe bombers in the port of Eupatoria on the 29 October 1941. To this day, the identity of the ship remains an open debate.
After the war
After the war, Constantin Costăchescu served as an instructor for Romanian submariners and as a professor at the Navy Academy in Constanţa, teaching future navy officers spatial geometry. He died in the 1980s, after a hard fall on ice during a cold winter in Constanţa.
Because of the Communist regime, his merits were never acknowledged.
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- Antony Preston, Warship 2001-2002, Conway Maritime Press, 2001. p. 76
- Richard Compton-Hall, Submarines at War 1939-1945, Periscope Publishing, 2004, p. 127
- Koslinski N., Stanescu R. (1996). Marina Romana in al Doilea Razboi Mondial (The Romanian Navy in the Second World War) vol. I. Fat-Frumos.
- Victor Nitu. "NMS Delfinul".