Massively outnumbered by the Soviet Union's 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 navy began to clear the Soviet mines defending the port and to lay their own minefields protecting the route between Constanța and Odessa. "Mărășești" was twice attacked off Mangalia, Romania, on 6 November 1941 by the , but was missed with all four torpedoes. Sometime during 1941–1942, the ship's turbines were damaged and limited her to a speed of . On 20 April 1942, after the ice had melted, "Mărășești", "Mărăști" and the destroyer escorted the first convoy to Ochakov, although the Romanian destroyers were generally used to escort ships between the Bosporus and Constanța. On the nights of 22/23 and 24/25 June, "Mărășești", "Regina Maria" and her sister covered the laying of defensive minefields off Odessa. After Sevastopol surrendered on 4 July to the Axis, a direct route between the port and Constanța was opened in October and operated year-round.