This paper was presented at ETT99/SATNAV99 Conference, held by DGON/NIN in Potsdam, Germany on 9th November 1999.

In the foreseeable future, Automatic Identification Systems (AIS) will be installed aboard all sea-going ships larger than 300 g.r.t. These new devices broadcast data at regular and short intervals, by means of which the ship can be identified and tracked. Further data can be transmitted to provide additional information on the ship's motion, navigational status, intended voyage and cargo. The transmissions can be received by every interested party having an appropriate receiver both at sea and ashore. With these capabilities, AIS adds a new information quality to maritime traffic, which is relevant not only for ship/ship but also for VTS/ship interaction. This paper describes the genesis of the new systems and their operational and technical aspects. It continues with a discussion of their standard and extended applications and their – so far – unexploited potential. Where relevant, the results of R&D work and practical tests are mentioned.