Looking like a fishing boat is effective deterrance to a "search and destroy" drone. Only by boarding pitate ships can we be sure they are pirate ships. Even then it is difficult, as non-pirate boats must arm themselves against pirate ships.
Good point. Given that the default position of the Media is to report “Dead Civilians”, when in fact they are terrorists, drone strikes against small vessels could quickly become counterproductive.
One rule of thumb we can apply is that if the boat has an engine capable of speeds exceeding 15 knots, and there are arms aboard, we put a bullet through the engine and give them some paddles to get home with.
This is sounding more like the original mission of the Swift Boats in the Vietnam war, interdicting arms traffic offshore.
The mission changed and they went upriver later, iirc.
Few boats are going to have enough armor to resist RPGs and shallow enough draft to do the job. Maneuverability and speed are always in a tradeoff over crew protection.
Using drones to shadow such vessels and separate the fishermen from the pirates and track them might be the way to go.
If there was some way to 'tag' the boats (RFID transponders?) and know which was which, even the 'dual use' vessels could be monitored and appropriate action taken.