When the Axis Powers launched Operation Barbarossa in June 1941, Romania joined the invasion with the aims of recovering the provinces of Bessarabia and Northern Bukovina, which were occupied by the Soviet Union the previous year.

[5] On 9 July 1941, one week after Romania launched Operation München, the Romanian Navy's 250t-class torpedo boat Năluca (Captain Horia Popovici) and motor torpedo boats Viscolul and Vijelia were informed by the Romanian gunboat Stihi that the periscope of an enemy submarine was sighted near Mangalia.

Năluca was the first to arrive at the scene and subsequently spotted and engaged the Soviet Shchuka-class submarine Shch-206 (Captain S. A. Karakai).

In the first part of the battle, Năluca attacked the submarine with 20 mm rounds, but the latter submerged in order to escape.

[6][7][8][9] The result of this engagement secured Mangalia for the rest of the Second World War, as no other Soviet warships were subsequently sighted near the port.