(United States)

Notes: Based on the successful Swedish SAK MK1/2/3 57mm, the Mk110 was selected in 2003 to arm the USCG’s new WMSL (large cutter) class, and in 2004 the USN announced it would serve as the CIGS (close-in gun system) aboard the Zumwalt class destroyers and the projected CG(X) class cruisers.

The guns are manufactured in Louisville, KY. Testing was completed in 2006, exceeding all expectations. When not in use, the barrel depresses inside a trap-door structure protruding from the deck, enhancing the turret’s low-observable characteristics. Fire control is via the AN/SPQ-9B radar or other designator system.