Business Insider has a post reporting the successes of Ukraine’s kamikaze USV program as evaluated by Ukrainian intelligence chief Kyrylo Budanov. It included some information I had not seen in earlier reports.

“Budanov noted one occasion when a sea drone had been destroyed as it approached Russia’s Admiral Essen frigate in Sevastopol Bay…”It seemed unsuccessful. But the blast wave, because it was destroyed about 100 meters from the ship, and the charge was quite powerful, the wreckage completely damaged some of the ship’s electronic equipment, antennas, certain systems, and the hydroacoustic system. And it took 3-and-a-half months to repair,” Budanov said.”

This suggests to me that because kamikaze USVs with large explosive charges can do significant damage at 100 meters, then crew served machine guns on the target vessel are not sufficient protection.

These threats need to be destroyed well before they get within 100 meters (110 yards) of their target.