Ukraine's maritime forces have been dealt a heavy blow by the Russian intervention in Crimea, with 12 of its 17 major warships and much of its naval aviation assets falling under Moscow's control.
In the eight days since the controversial referendum on 16 March that opened the door for Crimea to be absorbed in the Russian Federation, almost every Ukrainian naval base and ship on the peninsula has been seized by Russian forces or local pro-Moscow self defence units.
The scale of the crisis facing the Ukrainian navy is apparent from the fact that around 12,000 of its 15,450 personnel were based in Crimea when Russia intervened on 27 February. Over the past three weeks, the majority of the Ukrainian military personnel on Crimea have defected to the Russian military or resigned from military service, according to announcements by the new pro-Kremlin administration in Crimea. Some independent media reports appear to broadly support Russian claims in this regard.
In a major blow to its pride, the Ukrainian navy's commander, Admiral Serhiy Hayduk, was arrested by Russian forces when the navy headquarters in Sevastapol was seized on 19 March, and was unceremoniously dropped off by Russian troops at the new "border" checkpoint with Ukraine in the north of Crimea. Those of the admiral's sailors who wanted to continue to serve in Kiev's navy had to make their own way off the peninsula in civilian cars or on public transport.
In Sevastopol, the Russians seized intact four major warship, the Grisha V-class frigates Ternopil and Lutsk , the Pauk-class corvette/patrol vessels Khmelnytskyi , and the Bambuk-class command ship Slavutych , as well as Ukraine's only submarine, the Foxtrot-class Zaporizhzhia . Also seized in Sevastopol was the ocean-going tug Korets .
At the same time as Russian forces were boarding Ukrainian vessels in Sevastopol, other special forces units and armed civilians were seizing Ukraine's Naval Base South at Novoozerne, on the north west coast of Crimea. Seven Ukrainian warships, including the Ropucha I-class landing ship, Kostiantyn Olshansky , had been blockaded in the base on Lake Dunuzlov since the start of the crisis after the Russian navy sank the hulk of two warships in the access channel leading to the sea. The Natya-class minesweeper Cherkasy unsuccessfully tried to open a passage by pulling away one of the blocking ships on 21 March although a Russian warship moved to block the escape attempt, according to a video posted on a social media site.
Ukraine's 10th Saski Naval Air Brigade, which controlled all of the country's maritime aviation assets, fared better at evading the Russian occupation, and managed to get a number of its aircraft and helicopters airborne from Novofedorivka airbase to fly to bases in mainland Ukraine on 5 March. This included one Kamov Ka-27PL and three Mil Mi-14PL maritime helicopters, one Beriev Be-12 amphibian and two Antonov An-26 transports, according to film of the escape posted on social media sites. More than a dozen aircraft and helicopters which were undergoing maintenance had to be left behind. The long-term sustainability of the Ukrainian navy's surviving helicopters is uncertain after the pro-Russian administration in Crimea nationalised all state owned enterprises, including the Sevastopol Aviation Enterprise, which had provided long-term maintenance and overhaul of the services helicopters.
The rump of the Ukrainian navy is now concentrated at the service's Naval Base North at Odessa. This force boasts less than half a dozen large surface combatants as well as several small patrol craft. It includes the pride of the navy, the Krivak III-class frigate Hetman Sagaidachny , which was returning from an Indian Ocean counter-piracy mission as the Crimea crisis broke and was able to divert to Odessa. The frigate and its embarked Ka-27 helicopter have since carried out one maritime security patrol, off Ukraine's southern western territorial waters, over a seven day period up to 21 March. According to the Ukrainian Ministry of Defence the ship encountered four Russian ships and two Mil Mi-35 attack helicopters probing the country's territorial waters and airspace but the two sides did not engage each other.
Ukraine's navy now faces an uncertain future. As well as losing the bulk of its ships, helicopters and aircraft, it headquarters building, much of the service's signals intelligence, training, administration, maintenance, and logistics infrastructure has now been lost. This includes the service's main underground ammunition storage site at Inkermann valley, outside Sevastopol. Russian naval patrols have also blockaded the access to the Sea of Azov to the east of Ukraine, cutting off military and civilian access to ports in the east of the country.
On 24 March, the last remaining major unit of the Ukrainian navy on Crimea still holding out - the 750 strong 1st Marine Battalion at Feodesia in the east of the peninsula - was overrun and many of its personnel were arrested. The unit's commanders had been negotiating with the Russians to be allowed to drive off Crimea with all their vehicles, weapons, and equipment so its dispersal will be a significant blow to its morale and unit cohesion.
On 24 March, the Russian authorities claimed to have seized some 189 Ukrainian bases on Crimea, including final sections of the Balbek airbase held by personnel of the 204th Tactical Aviation Brigade; the airbase was overrun by Russian Spetsnaz troops in a dramatic assault two days earlier. The brigade's 39 Mig-29 fighters were seized in the first days of the crisis. The Ukrainian air force's 174th Air Defence Regiment base at Fiolent on the outskirts of Sevastapol was overrun on 21 March and its inventory of S-300 surface-to-air missiles seized. The fate of the last two Ukrainian air defence regiments on Crimea, the 55th regiment at Yevpatoriya and 50th regiment at Feodesia - and their S-300 and Buk-M1 weapon systems - is uncertain.
Some 2,000 Ukrainian air force and air defence personnel were believed to be based in Crimea before the crisis, along with a similar number of paramilitary police and border guard personnel. No major Ukrainian army units were trapped on Crimea, so the service has largely escaped the convulsions that have seriously impacted the country's navy and air force.