UKRAINE WITHOUT A NAVY TERRIFIES THE RUSSIANS

There are submersible drones too with sonar reflectors or dampeners that can navigate autonomously during targeting phase onto "locked on" targets. They are more cost efficient especially while engaging submarines and surface ships. They have ISR roles/ capabilities and can also swarm into " formational" attack roles as reactive/ responsive mines.

They probably have been inspired by the “barchini”, the italian royal navy small boats, used by the incursori (special operations personnel of the navy) in the Adriatic Sea against the Austrian-Hungarian Navy, during first world war. Similar tactic: they were launched by main ships or departed from Italian coast. At about 250 mts from their target, the sailor blocked rudder and throttle of the barchino and jumped outboard, in the sea. The boats were full of explosive. They were invented by Italian admiral and hero of war, Nazario Sauro. May the victory be with Ukraina: may the spirit of Italian brave sailors be with Ukrainian people!

Those marine drones travel at 50mph, no ship can go that speed so the drone can easily catch up. Ukraine has been very clever with telling commercial ship owners that if their ships are going to and from Russian ports then they will be treated as valid military targets - they have given ship owners two weeks notice to get their ships out of the black sea - and large commercial ships cannot dodge and weave, and will not be carrying the means to destroy the naval drones. A lot of Russian oil, and even more of their wheat goes via Black Sea ports... This could really cripple Russia.