“A close-in weapon system (CIWS) is a point-defense weapon system for detecting and destroying short-range incoming missiles and enemy aircraft which have penetrated the outer defenses, typically mounted on a naval ship. Nearly all classes of larger modern warships are equipped with some kind of CIWS device.”
Please try not using initialisms that a general audience won’t know. That’s why i had to look up the previous one and quoted the info so other people wouldn’t have to look it up also. USV doesn’t even show up in a googling
EDIT
I found it, USV means a drone boat