Fun fact: CIWS are not actually that great for shooting at pirate skiffs, since 1. They typically require radar lock before being able to fire in the first place and a fiberglass dinghy has a really low radar cross section and also typically not enough doppler since it doesn't go at anti-ship missile speeds. 2. The manual override for this behavior has "rather poor" UX to say the least, since it is not really a core feature of the system. The whole point of a CIWS is that it's only used in the last few seconds of an engagement at speeds at which humans cannot react. 3. The ammunition used is typically subcaliber armor piercing discarding sabot type rounds. They are optimized at taking down an anti ship missile if they hit by destroying the guidance section of the missile or (if you get a lucky hit) detonating the warhead. They will just go through a pirate skiff and come out the other end. The skiff is lighter than water so it won't sink.

What you want is a 76mm gun or a RWCS like the https://en.wikipedia.org/wiki/Hitrole, preferably firing airburst and/or flechette rounds. They have a much better probability to hit and disable the target than a CIWS.

Source: Used to be a weapons engineering officer for the Royal Netherlands Navy. A ship I was on caught some pirates off the coast of Somalia once and (after the pirates were taken into custody) we tried to sink their vessel with the CIWS, leading to the lessons in the post above. It turns out it is really tough to sink something lighter than water by punching holes into it and the expected "the CIWS will saw the dinghy in half" effect was much less than we hoped.