Massively outnumbered by the Black Sea Fleet, the Romanian ships were kept behind the minefields defending Constanța for the next several months, 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; the submarine fired two torpedoes at "Regina Maria" that same day, but missed. 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. On 1 December "Regina Maria", her sister ship and "Mărăști" were escorting a convoy to Odessa when a submarine unsuccessfully attacked the convoy. It was quickly spotted and depth charged by "Regina Maria" and "Regele Ferdinand" with the latter claiming a kill. Soviet records do not acknowledge any losses on that date. "Regina Maria" and "Regele Ferdinand" escorted another convoy to Odessa on 16–17 December, the last one before ice closed the port.