Pretty much what the title says. I’ve heard various things about it, including people saying you could use it to stop terrorist boats approaching, etc. But if you can’t get a target lock on a fiberglass boat, how do you mow down the approaching terrorists? I would assume that if the target acquisition system is primarily a radar, it would have a tough time with a target at the water surface (since the ocean waves also reflect radar), traveling slowly, among a literal sea of noise. I mean, it might be able to lock on, but it might not, and I would not expect it to be reliable.
The block 1b revision that started in 1998ish added a forward-looking infrared sensor to allow targeting of surface vessels. This can be done either automatically or with operator intervention.
News story on the upgrade:
On a side note, it’s kinda nuts that our opponents use AK-47s and suicide bombers in boats, and we have automatic heat-tracking gatling-gun killing machines you can read about on Wikipedia. Yet still they can send ten people or so and change a superpower’s trajectory for the next 30+ years. Seems like surface vessel target acquisition is the least of our defense problems.
It’s CIWS, not CWIS. Close-In Weapon System.
Despite the fact they pronounce it see-whiz which might lead you to spell it c-wiz or c-wis.