and provides security operations as approved by the Chief of Naval Operations, in coordination with the Commandant of the Marine Corps, As of June 27, 2008, MCSFCO was restructured from a company to a battalion. A similar sister battalion is stationed with the West Coast submarine base in Bangor, Washington. In addition to Marine Corps security forces, they are joined by Navy Master-at-Arms and Navy Law Enforcement/Security Officers with the 6490 designator. Both Masters-at-Arms and Navy Law Enforcement/Security Officers are part of the larger U.S. Navy Security Forces. United States Coast Guard (USCG) Maritime Force Protection Unit One of the first Maritime Force Protection Units was established by the United States Coast Guard (USCG) at Kings Bay. The Maritime Force Protection Unit provides escort protection for the submarines as they transit on the surface, to and from their homeports. The unit includes some smaller vessels, and two Marine Protector class cutters, the and the . The Sea Dragon and Sea Dog'', and two other cutters, the and , although crewed by sailors from the Coast Guard, they were ordered, and paid for, by the Navy. For protecting submarines the Navy requested a slightly modified design, which added gyrostabilized machine gun, with advanced optics, which was fired under remote control from the ship's bridge. The gyrostabilized gun's greater long range accuracy made it more appropriate for intercepting speedboats laden with a suicide bomb. Trident Refit Facility The Trident Refit Facility (TRF) is the largest tenant command at Kings Bay and has kept a significant portion of the United States Fleet Ballistic Missile submarines at sea since 1985. TRF provides quality industrial-level and logistics support for the incremental overhaul, modernization, and repair of Trident submarines. It also furnishes global submarine supplies and spare parts support. In addition, TRF provides maintenance and support services to other submarines, regional maintenance customers, and other activities as requested. The Trident Refit Facility possesses the largest covered drydock in the world, measuring long, wide, and deep. A state-of-the-art Magnetic Silencing Facility (MSF) provides degaussing services, including ranging and the removal of permanent magnetism for submarines of the U.S. Navy and the British Royal Navy, as well as for steel-hulled surface warships. The MSF is the only facility of its kind on the East Coast, and it is also used for research for development of future magnetic systems. The Defensive Ordnance Support Facility maintains and stores all of