Kyiv reported on Monday that its Bayraktar TB-2 drones sank two Russian patrol boats near Snake Island in the Black Sea as experts warned that the tides may be turning as Russia fails to leverage its dominance of the waters.

"Two Russian Raptor boats were destroyed at dawn today near Snake Island," Ukraine's Defense Ministry said in a statement distributed on social media.

The ministry also released grainy black and white ariel footage showing an explosion on a small military vessel.

"The Bayraktars are working," Valeriy Zaluzhnyi, the commander in chief of the Ukrainian Armed Forces, was cited as saying in the statement, referring to the Turkish-made military drones.

Raptor patrol boats can carry up to three crew and 20 personnel. They are usually equipped with machine guns and used in reconnaissance or landing operations.

Snake Island became a symbol of Ukrainian resistance after a radio exchange went viral in which Ukrainian soldiers rebuffed demands from crew of a Russian warship to surrender.

The Russian ship involved, the Moskva, sank in the Black Sea in mid-April following what Moscow said was an explosion on board. Ukraine said it had hit the warship with missiles.

Balance of power

Experts say that while Russia may rule the Black Sea, any amphibious assault on the Ukrainian coast seems risky since Kyiv's missiles threaten to destroy Russian ships if they get too close.

According to British intelligence sources, Russia operates around 20 warships in the Black Sea, where the balance of power is now static since Turkey blocks any access by vessels belonging to a warring party under the Montreux Convention.

"It's their 'Mare Nostrum,'" said Capt. Eric Lavault, a spokesperson for the French navy, a reference to the Latin term meaning "Our Sea" used in ancient Rome to describe the Mediterranean.

The fact that all the other Black Sea countries either already belong to NATO or hope to join the Western alliance has not cowed Russia's claim to supremacy.

On paper, the recent capture of the coastal Ukrainian city of Mariupol and Russian control of the entire Sea of Azov coastline should underline Russian dominance and allow Moscow's troops to establish a direct logistics link between its fighters in the Donbass region and the eastern port of Novorossiysk, Lavault said.

But since the surprise sinking last month of the Russian warship Moskva all bets are off.

The disappearance of the Russian flagship has created great uncertainty for the attackers along what is still a Ukrainian-controlled coastline between Odessa and Romania.

This is not thanks to Kyiv's navy, which has been destroyed, but to land-based missiles like the Neptune – believed to have delivered the fatal blow to the Moskva – and, soon, the Harpoon that Britain is to deliver to Ukraine.

The impact of the Moskva's sinking on Russian planning may well prevent any attempt by the Russian navy to land near Odessa with the aim of surrounding the Ukrainian heartland and linking up Russian forces with separatists in the Moldovan Transnistria region.

"That zone presents a threat that the Russians must take into account," said defense expert Igor Delanoe at the French-Russian Monitor, a political analysis body based in Moscow.

Any such landing is currently "out of reach" for the Russians, said Delanoe.

Russian progress in the Donbass region could open up new options, he said, "but they will have to neutralise the coastal defences," he cautioned.

'Not Russia's anymore'

Russian forces have had great trouble locating and destroying Ukrainian surface-to-air missiles because of their mobility, said Michael Petersen, director of the Russia Maritime Studies Institute and an associate professor at the U.S. Naval War College.

"I suspect that would also be the case for any mobile coastal defense cruise missile system that Ukraine may have," he said, adding that the exact number of Neptune missiles – which have a range of some 300 kilometers (200 miles) – available to Ukrainian forces was unknown.

Russia's failure to establish air superiority, and its apparent inability to precision-target missiles, are not helping its efforts to knock out Ukraine's coastal defenses, added French navy spokesperson Lavault.

He said this had allowed the defenders to create "a maritime cordon sanitaire" and threaten Russian southern supply lines between Kherson and Mykolaiv.

In addition, Ukraine has deployed mines, and is expected to take delivery of naval surface drones promised by the U.S., although it is not certain that they will be armed.

"More likely, if Ukraine is provided with unmanned systems, they would be used to provide surveillance and reconnaissance for weapon systems," Petersen said.

British Defense Secretary Ben Wallace meanwhile went as far as contesting Russia's centuries-old supremacy in the Black Sea altogether.

"The Russians can't control the Black Sea," he told Sky News. "It's not theirs anymore."

Whatever the outcome of the Ukraine war, Russia will not give up its Black Sea role quietly, experts agreed.

But as other Black Sea countries deploy their own coastal missile systems based on Ukraine's example, Moscow's role will become harder to maintain.

"Certainly Russia will be less secure in the Black Sea than they were before the war," said Petersen.