Around midnight on March 5, the Russian navy used tugboats to maneuver the 9,000-ton hulk of the anti-submarine ship Ochakov into position, placing the hull broadside — side-on — to the roughly 220-meter-wide (720-foot-wide) channel that leads to Donuzlav Lake. Using explosives, they scuttled the 173-meter-long ship, leaving it partially submerged and on its side, preventing large ship traffic from using the inlet. Though the entrance itself is 400 meters wide from jetty to jetty, ships must use the center of the cleared channel to avoid running aground.
Since the beginning of March, Russian ground, air and naval forces have isolated Crimea from mainland Ukraine. Across the peninsula, all Ukrainian military installations have been systematically taken over or surrounded and contained, with the purpose of rendering them useless as a coordinated fighting force. To neutralize any ability to oppose Russian forces, Moscow has relied on overwhelming numbers of military assets. Prior to scuttling the Ochakov, the Russian navy had utilized 10 ships to contain the Ukrainian navy element in Donuzlav Lake.
The improvised blockage is an efficient, semi-permanent way for Russia to free up military assets for other uses. Although the Ukrainian navy is relatively weak compared to the Russian Black Sea Fleet, the Kremlin's operational planners still want to deny Ukraine the ability to concentrate force. Isolating Donuzlav Lake thus is a prudent move while Russia, Ukraine and the West haggle over Crimea. The removal of a scuttled ship in shallow waters can be very complex, expensive and time consuming. Given the present circumstances, with Russian forces in de facto control of Crimea, the Ukrainian navy has little to no ability to remove the obstacle. A large portion of Ukraine's naval forces will thus be sidelined from the ongoing tensions for at least the near future.
Trapping Ukraine's warships may also give Russia a new bargaining option. Much of the present-day Ukrainian navy was appropriated from the former Soviet navy after the breakup of the Soviet Union in 1991. In time, Russia might choose to retake part of its "lost fleet," depending on how negotiations play out with Ukraine. Reports from Crimea indicate that Russian ships have demanded Ukrainian sailors disembark in Sevastopol — orders that so far have been refused. Russia has refrained from taking hostile action, possibly because boarding a ship can become complex and bloody if resistance is encountered. Russian forces have carefully avoided violence so far, seeking to bypass any incidents that could undermine Moscow's deeper geopolitical aspirations in Crimea.
Russia seems content to keep the besieged ships at Novoozerne contained as bargaining leverage. Ultimately, the main goal for Russia appears to be keeping all Ukrainian forces in Crimea paralyzed while deterring any military operation that seeks to alter the status quo on the peninsula. Dividing the Ukrainian fleet achieves this neatly.
