10.3 Classes of AIS dataThere are two classes of AIS data; each class supports a differentrange of AIS data.AIS data is defined as Class A or Class B. The sending andreceiving of Class A data is compulsory for larger vessels. You willtherefore be able to view all larger vessels on your AIS display.Class B data is applicable to smaller vessels and is not compulsory.You should not therefore assume that your AIS is displaying allsmaller vessels in your area.Note: Not all AIS receivers will decode all information and notall of the Class A vessels input all of the required AIS data. Forexample, some inexpensive AIS Class B receivers do not decodeand output information such as the ship’s name, IMO number andvessel draft/beam/length, destination and so on.Your AIS receiver or transceiver may support additional AIS datathat is not decoded by the multifunction display.The following table lists the AIS information that is decoded by yourmultifunction display. (Y = Yes; N = No):DataClass A(receive)Class B(send)Class B(receive)Ship’s name Y Y YType Y Y YCall sign Y Y YIMO number Y N NLength and beam Y Y YAntenna location Y Y YDataClass A(receive)Class B(send)Class B(receive)Draft Y N NCargoInformationY Y YDestination Y N NETA Y N NTime Y Y YShip’s position Y Y YCOG Y Y YSOG Y Y YGyro heading Y Y YRate of turn Y N NNavigationalstatusY N NSafety message Y N Y136 C-Series Widescreen user reference
