This is the best summary I could come up with:
Russia's defence ministry said it had repelled a Ukrainian attack with two sea drones on its naval base there.
But Ukrainian security service sources say the Olenegorsky Gornyak was hit and suffered a serious breach.
A video sent to the BBC by a source with Ukraine's security service appears to show the drone approaching a ship thought to be the Olenegorsky Gornyak.
The footage shows a vessel travelling right up to the side of a ship before the feed cuts out, apparently on impact.
Research by BBC Verify suggests Ukraine has carried out at least 10 attacks with sea drones- targeting military ships and Russia's naval base in Sevastopol, as well as Novorossiysk harbour in a previous attack.
Ukrainian defence sources have told CNN that sea drones had also been used in an attack on the Kerch Bridge to Crimea in July.
I'm a bot and I'm open source!