79AIS Receiver (Depending on versions)9About AISNAIS (The automatic identification system) used primarily forcollision-risk management and navigation safety. It automati-cally transmits and receives vessel information such as thevessel name, MMSI code, vessel type, position data, speed,course, destination and more. Information is exchangedamong the vessels and/or base stations on the VHF maritimemobile band. The information helps to identify other nearbyvessels or stations by displaying the received data ona plotter or a radar screen.AIS ClassesNThere are seven types of AIS stations; vessels, base stations,Search and Rescue (SAR), Aids to Navigation (AtoN), Searchand 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 onvessels; Class A and Class B.Under the Safety Of Life At Sea (SOLAS) convention, allSOLAS vessels, as described below, are required to install aClass A AIS transponder:s 5PWARDS OF GROSS TONNAGE ENGAGED ON INTERNATIONAL-voyages.s 0ASSENGER VESSELS IRRESPECTIVE OF SIZE ENGAGED ON INTENA-tional voyages.s 5PWARDS OF GROSS TONNAGE NOT ENGAGED ON INTERNATIONAL voyages.A Class B AIS transponder is designed to be interoperabilitywith Class A units, but not to impact the Class A network.Many commercial vessels, and some leisure craft, not clas-sified as requiring a Class A unit, choose to install a Class Bunit to avoid accidents at sea.Your vessel(Class B AIS)Other vessel(Class A AIS)Other vessel(Class B AIS)Base StationVessel information