A Perilous Time to Be in the Surface Navy

Not from submarines, mind you. Subs are expensive to buy, expensive to maintain and expensive to operate, given the cost of having well-trained crews. Badly-trained crews can be deadly for the boats. That cost is why one can probably count the navies that can run subs well on two hands and not use all your fingers.

No, I am referring to a development of the Russo-Ukrainian War: The unmanned surface vehicle (USV). Oh, they were around before as experimental stuff, but the Ukrainians rammed that technology to fruition at the sort of development speed unseen since the Second World War. Like the GIs who came up with things like Rhino tank, the Ukrainians are not being constrained by a ossified bureaucracy and their development cycle (idea->design->prototype->test->manufacture) is far quicker than that of the Russians.

The Ukrainian USVs have effectively denied much of the Black Sea to the Russian navy. The Russians can't get close enough to maintain a sea blockade, so Ukrainian grain exports have been continuing. Russian warships have been pushed back to bases far from the fighting.

What makes the USVs so deadly is their construction. They have very low to no freeboard, so their radar cross-section is very low. I would not be at all surprised if the top half of them are made of fiberglass, wood or carbon fiber, all of which are not radar reflective. They are propelled by electric motors and, by normally operating at relatively slow speeds, they would not have loud propeller cavitation, like a torpedo. They are likely undetectable by passive sonar at any meaningful range and, being small, they're not going to show up well on active sonar. There may be an optic mast/antenna that is about as thick as a broomstick and would be made of carbon fiber, again, hard to see on radar.

And they can pack a hell of a punch. A few hundred pounds of explosive, detonating at very close range, will blow a hole in the hull that will sink most ships that do not have good damage control equipment and crews trained for that. Which means that one good hit will kill most merchant ships or Russian navy warships.

It would not be terribly difficult to run enough of them to deny sea access to an area that is somewhat constrained by geography, such as the Red Sea. USVs may be able to loiter for extended periods. The drones could be programmed to know when to return to a designated point for recharging.

The defenses would be the same against torpedoes: Booms and nets. Which means that the ships so protected can't go to sea. The other defense is an alert topside watch, but maintaining the sharpness to look for a broomstick moving through the water on a 24/7 basis is almost impossible. The best time to run such an attack would be at night, which means that the ships have to be well-illuminated to look for a USV at close range.

And the answer to that would be a USV that has a pop-up short-range missile, such as a barrage of RPGs or something similar. Fire those off, discombobulate the crew and then hit with a few contact-USVs.

What does this mean for surface operations? Dangerous waters would be anywhere within several hundred miles of the coastline of an adversary. And if a freighter was converted to be a mothership to launch a swarm of one-way attack drones, the danger radius could be very large.

If the Taiwanese are not going all in on USV drone technology, I would be astonished. Which also means that the PRC's window to mount a successful invasion of Taiwan may be closing for a long time.