Brand new Russian Navy corvette VYSHNY VOLOCHEK was spotted transiting Dardanelles under tow of Russian Navy SAR tug PROFESSOR NIKOLAY MURU on Nov 6, in eastern direction, obviously heading for Sevastopol Navy Base, Black sea. What happened to brand new ship in her first mission (she was in Mediterranean since August, after joining Black Sea Fleet in June), is unknown. Maybe they decided to save a bit on fuel, who knows. Caravan was escorted by Turkish Coast Guard, as of 1630 UTC Nov 6 caravan was in Marmara sea proceeding towards Bosphorus at some 4.5 knots speed. 
Russian Navy Buyan-Class corvette VYSHNY VOLOCHEK, displacement 949 tons, launched 2016, commissioned 2018, Bkacl Sea Fleet, complement 52, armamaent missiles, guns. 
Russian Navy SAR tug PROFESSOR NIKOLAY MURU, MMSI 273544130, displacement 1200 tons, built 2014, base port Sevastopol, Black sea.