Massively outnumbered by the Black Sea Fleet, the Romanian ships were kept behind the minefields defending Constanța for several months after the start of the war. They spent that time training for convoy escort operations. Beginning on 5 October, the Romanians began laying minefields to defend the route between the Bosphorus and Constanța; the minelayers were protected by the destroyers. After the evacuation of Odessa on 16 October, the Romanians began to clear the Soviet mines defending the port and to lay their own minefields protecting the route between Constanța and Odessa. During the winter of 1941–1942, the Romanian destroyers were primarily occupied with escorting convoys between the Bosporus and Constanța. On 1 December "Mărăști", "Regina Maria" and her sister were escorting a convoy to Odessa when a submarine unsuccessfully attacked them. It was quickly spotted and depth charged by "Regina Maria" and "Regele Ferdinand" with the latter claiming a kill. Soviet records, however, do not acknowledge any losses on that date.