Ship movement service

Ship movement service (short: SMS;  | also: ship movement radiocommunication service) is – according to Article 1.31 of the International Telecommunication Union´s (ITU) Radio Regulations (RR) – defined as «A safety service in the maritime mobile service other than a port operations service, between coast stations and ship stations, or between ship stations, in which messages are restricted to those relating to the movement of ships. Messages which are of a public correspondence nature shall be excluded from this service.»