Air defence in naval tactics, especially within a carrier group, is often built around a system of concentric layers with the aircraft carrier at the centre. The outer layer will usually be provided by the carrier's aircraft, specifically its AEW&C aircraft combined with the CAP. If an attacker is able to penetrate this layer, then the next layers would come from the surface-to-air missiles carried by the carrier's escorts; the area-defence missiles, such as the RIM-67 Standard, with a range of up to 100 nmi, and the point-defence missiles, like the RIM-162 ESSM, with a range of up to 30 nmi. Finally, virtually every modern warship will be fitted with small-calibre guns, including a CIWS, which is usually a radar-controlled Gatling gun of between 20mm and 30mm calibre capable of firing several thousand rounds per minute.
Is there an answer to this question (If it cannot be answered, say "unanswerable"): What is the rate of fire for a radar-controlled Gatling gun of 20 and 30 millimeter?
several thousand rounds per minute