Boat swarms, like cheap cruise missiles, are more useful for shore defense. Carriers operate further out, either out of range, or plenty of time to detect them.

Boat swarms, like cheap cruise missiles, are more useful for shore defense. Carriers operate further out, either out of range, or plenty of time to detect them. But it may make amphibious operations impossible. They are also something new that nobody has developed defenses for. The US has working on small boat defense, so maybe improved guns will work for drones. One variant that would be interesting are semi-submersible drones.