The GMDSS is a system put in place internationally to enable rapid alerting of a marine distress situation to take place. This in turn enables search and rescue proceedings to be implemented with the minimum of time lost.

The system involves the use of one or more methods of communication including Digital Selective Calling (DSC), Emergency Position Indicating Radio Beacons (EPIRBS), Search and Rescue Transponders (SARTS) as well as voice radiotelephone and Inmarsat communications.

From the 1st February 1999, GMDSS was fully implemented. From this date also the MF/HF radiotelegraphy (Morse code) service in Australia came to an end after 87 years continuous service.

From 1st July 2002, DSC functions will be provided by two new stations at Charleville, Queensland and Wiluna, Western Australia and remotely controlled from an operations centre in Canberra. This service will be operated by TVNZ.

Maritime Communications Stations monitor the HF GMDSS frequencies and broadcast weather reports and navigational warnings at scheduled times. From 1st July 2002, this role will be taken over by State Government Authorities.

The system also provides for urgency and safety communications and the promulgation of maritime safety information (navigational and meteorological warnings and forecasts and other urgent safety information).

In other words, every ship is able, irrespective of the area in which it operates, to perform those communication functions which are essential for the safety of the ship itself and of other ships operating in the same area.