| The AIS is a important key device used to indicate AIS target symbol and information on RADAR / ECDIS screen. •AIS target and also ARPA target are shown on same screen of RADAR / ECDIS. Comparison between these targets is useful to know maneuvering condition against other ships. •AIS target is shown as vector symbol formed by course and speed, which is referred with the received information real-timely from other ships. AIS target is more accurate information than ARPA. therefore AIS information is suitable for collision avoidance. •AIS symbol is kept showing on the screen without any influence happened by characteristics of radar, unless the other ships are out of VHF range. That is why the AIS target is never shielded by reflection of ground, rain or cloud, and eliminated by adjustment of anti-sea-clatter or anti-rain-clatter. •Indication of AIS target symbol is switch-able. |