The IMO requires AIS use by all vessels >500GT, for any vessel >300GT that is on an “international voyage” and for all passenger vessels: IMO Revised Guidelines for the Onboard Operation Use of Shipborne AIS – A.1106(29) 22 AIS should always be in operation when ships are underway or at anchor. If the master believes that the continual operation of AIS might compromise the safety or security of the ship or where security incidents are imminent, AIS may be switched off. Unless it would further compromise the safety or security, if the ship is operating in a mandatory ship reporting system, the master should report this action and the reason for doing so to the competent authority.
In addition, many countries and intergovernmental agencies such as regional fisheries management organizations are creating AIS requirements within their waters, so we expect an increase in AIS use in the coming years. For example, as of May 31, 2014, all European Union flagged fishing vessels over 15 meters in length are required to be equipped with AIS and as of March 1, 2016, all commercial U.S. flagged fishing vessels over 65 feet in length are required to be equipped with AIS.