The Coast Guard in partnership with the Marine Exchange of Alaska has established an Automated Identification System (AIS) site in the Unimak pass to assist with maritime domain awareness.
AIS is a shipboard broadcast system that acts like a transponder, operating in the VHF maritime band. The system allows a shipboard radar to display a mark for every significant ship within radio range. Each mark displays the corresponding ship's speed, heading, name, size, call sign, registration number, classification and other information. AIS has the same range-limiting factors of radio broadcasts however, the system's coverage area can be expanded by shore based repeaters. The system's range at sea is approximately 20 nautical miles.
The Unimak Pass AIS site is the ninth of 11 planned sites established in Alaska. Automated Identification System sites
have been established as part of a partnership between the Coast Guard and the Marine Exchange of Alaska. The project began in late 2003. The Coast Guard regularly uses AIS to improve its awareness within the maritime domain. AIS allows the Coast Guard command center here to monitor, in real time, the movements and positions of high capacity passenger vessels, Alaska Marine Highway System ferries and most larger commercial vessels within major ports. The availability of real time position information allows the Coast Guard to better coordinate search and rescue efforts and patrols for homeland security.
Originally designed to prevent collisions, AIS has proven to be very useful for homeland security. Using AIS the Coast Guard can verify that a ship is following its intended route. The Marine Exchange collects and formats AIS information and produces a visual representation available for use by ports and vessel managers. The Coast Guard has contracted with Marine Exchange for access to this information enhancing our maritime domain awareness.
The International Maritime Organization has established mandatory carriage requirements for approved AIS equipment under
the Safety of Life at Sea Convention. AIS is also mandated by the Maritime Transportation Security Act
Unimak Pass is part of the great circle route that links the Pacific Northwest and the Far East.