In this image taken from video released on Friday, Aug. 4, 2023, a drone manoeuvres as it approaches a vessel claimed to be a Russian large landing ship, the Olenegorsky Gonyak, close to the Black Sea port of Novorossiysk. Russia had accused Ukraine of attacking its Black Sea navy base in the port of Novorossiysk with sea drones.

Ukraine, a nation with virtually no navy, humiliated Russia's mighty Black Sea Fleet using cheap, fast, disposable drones. Combined with artificial intelligence, drones are set to change the nature of naval warfare. But are the world's militaries prepared for the risks?