Sea drones

How Ukraine is using sea drones to deter Russia's navy in the Black Sea

From CNN staff

Ukraine said it had carried out a sea drone attack on a Russian naval base, as dramatic videos appeared to show a damaged Russian warship listing heavily in the Black Sea on Friday.

Social media images showed the ship being towed near the Novorossiysk naval base, despite earlier claims by the Russian defense ministry that the attack had been repelled.

A Ukrainian source told CNN that a sea drone with 450 kilograms of TNT had attacked the ship and claimed there were about 100 Russian servicemen aboard.

“A big navy ship Olenogorsky Gornyak was hit,” the source told CNN. “As the result of the attack, the Russian ship has received serious damage and is not able to fulfill its duties."

Rare access to Ukraine’s sea drones: Perched on the banks of a secret lake, CNN was given exclusive access to the base where much-vaunted sea – or surface – drones are tested.

The Ukrainian-made surface drones are armed with 300 kilograms (about 660 pounds) of explosives and can hit a target 800 kilometers (about 500 miles) away.

A pilot who goes by the call sign "Shark" said the drones are easy to control and have limited the Russian navy's movements. Equipment on Russian ships is designed to attack other ships, according to the drones' developer, rendering the vessels' defenses ineffective.

Naval drones were used to strike the Kerch bridge — which links Crimea to mainland Russia — earlier this month, and they could prove to be vital against Russian threats on ships after the country withdrew from the Black Sea grain deal.