Icom IC-M506 Instruction Manual - Page 88

9 AIS RECEIVER (Depending on versions) ■■About AIS AIS (The automatic identification system) is primarily used for collision-risk management and navigation safety. It automatically transmits and receives vessel information, such as the vessel name, MMSI code, vessel type, position data, speed, course, destination and more. Information is exchanged among the vessels and/or base stations on the VHF maritime mobile band. The information helps to identify other nearby vessels or stations by displaying the received data on a plotter or a radar screen. Other vessel (Class B AIS) Other vessel (Class A AIS) Vessel information Your vessel (Class B AIS) Base Station 79 ■■AIS Classes There are seven types of AIS stations; vessels, base stations, Search and Rescue (SAR), Aids to Navigation (AtoN), Search and Rescue Transmitter (AIS-SART), MOB (Man OverBoard) and EPIRB (Emergency Position Indicating Radio Beacon)AIS. There are two classes of AIS units, which are installed on vessels; Class A and Class B. Under the Safety Of Life At Sea (SOLAS) convention, all SOLAS vessels, as described below, are required to install a Class A AIS transponder: • Upwards of 300 gross tonnage engaged on international voyages. • Passenger vessels, irrespective of size, engaged on inter- national voyages. • Upwards of 500 gross tonnage not engaged on international voyages. A Class B AIS transponder is designed to be interoperability with Class A units, but not to impact the Class A network. Many commercial vessels, and some leisure craft, not classified as requiring a Class A unit, choose to install a Class B unit to avoid accidents at sea.