Inconclusive Submarine Campaign Submarine warfare in the Black Sea in World War II during 1943 involved engagements between submarines of the Soviet Black Sea Fleet attacking Axis merchantmen defended by Romanian and German naval warships, as well as and German U-boats attacking Soviet merchants on the eastern Black Sea.

These engagements were a part of the Black Sea campaigns between Axis and Soviet naval forces.

At the beginning of the year the Soviet navy had 18 operable submarines (and 11 on refit), and organized them into "wolf packs" of groups of 3 with an attempted coordination with aircraft (though reports were often late).

Soviet submarines have been estimated to have sunk 20 targets (34,000 GRT) while suffering less losses: a better result compared to the campaigns of 1941 and 1942.

[39] This improvement forced the Germans to create a proper anti-submarine warfare unit: the 1.