Russia's Pacific Fleet submarines parade off the port city of Vladivostok during the Navy Day celebrations on July 2023.PAVEL KOROLYOV/AFP via Getty ImagesRussia's deployed three of its cruise missile submarines to the larger Black Sea area, Ukraine says.The Black Sea Fleet has six improved Kilo-class subs, including one that was damaged by Ukraine last year.The fleet's surface vessels have abandoned its base in Crimea amid major Ukrainian missile strikes.The Russian navy has simultaneously deployed three of its cruise missile submarines in waters within the general Black Sea area, Ukraine's navy says.The subs, likely improved Kilo-class vessels, are out in force just weeks after the last Russian Black Sea Fleet patrol boat left its base in Crimea following relentless Ukrainian attacks.