PL and PM type patrol vessels became important and this has also been achieved. As a final measure, by equipping JCG ships with remote control turrets incorporating automatic tracking functions applied to the ship's machine cannon, precise shooting became possible. Due to Japan's increased focus on grey-zone challenges around the Senkaku Islands, JCG's facilities on Ishigaki Island have been expanded so that 12 large patrol vessels can be stationed there. Ten and two s have been homeported at Ishigaki, along with housing for up to 600 crew, making Ishigaki JCG's largest base, surpassing JCG's facilities at Yokohama. Another half dozen ships including three are stationed north of Ishigaki at JCG's 11th Regional Coast Guard Headquarters at Naha. Statistics The JCG operates 455 watercraft, these include the following: Patrol vessels: 121 Patrol craft: 234 Special guard and rescue craft: 63 Hydrographic survey vessels: 13 Aids to navigation evaluation vessels: 1 Buoy tenders: 2 Aids to navigation tenders: 18 Training boats: 3 Aircraft The JCG operates 74 aircraft, these include: Fixed Wing: 27 Helicopters: 46 Vehicles The JCG does not have any emergency vehicle but civilian vans for transporting goods and personnel while some minibus such as Nissan Civilian and Toyota Coaster with distinctive markings are being used for transporting prisoners or illegal immigrants that were captured by the Coast Guard. Armaments As described above, the JCG is not a military but a civilian organization, so the rules on the use of weapons are based on those of police officers, not self-defense officers. Vessel-mounted weapons Because the Allied countries wanted to maintain the disarmament of Japan, the weapons allowed to be carried by the MSA were restricted to only small arms in the earliest days. However, following the outbreak of the Korean War, the need to strengthen the security capability of Japan became necessary, and starting in 1954, the installation of larger guns on MSA ships began. Initially ships of the MSA were permitted to carry Mark 22 3"/50 caliber gun for large vessels (PL type), Bofors 40 mm L/60 guns for medium and small size ships (PM and PS type), and Oerlikon 20 mm L/70 guns were mounted on small patrol boats (ARB type and auxiliary submarine chasers). Actually, however, the number of 40 mm guns was insufficient, and many of the PS type had 20 mm guns installed instead. From the 1970s, substitution of these old guns began. The 3-inch