The automatic identification system (AIS) is an automatic tracking system used for collision avoidance on ships and by vessel traffic services (VTS).

Automatic identification system (AIS) is an automatic tracking system used on ships and by vessel traffic services (VTS) to monitor marine traffic. AIS is primarily intended to allow ships to view marine traffic in their area and to be seen by said traffic. This requires a dedicated VHF AIS transceiver that allows local traffic to be viewed on an AIS enabled VHF radio and/or chartplotter while transmitting information about the ship itself to other AIS receivers.