THE GMDSS SYSTEM
The GMDSS introduced new technology that completely transformed maritime radiocommunications. It uses modern technology including satellite communications (COSPAS SARSAT, INMARSAT and IRIDIUM) and digital selective calling (DSC) enabling automatic transmission and reception of distress alerts over short and long distances. The system allows to quickly alert search and rescue authorities ashore (MRCC – Maritime Rescue Co-ordination Center) and vessels sailing in the vicinity of a ship in distress.
In addition, the GMDSS includes an internationally and nationally coordinated broadcasting network that allows ships to receive automatically maritime safety information (MSI – Maritime Safety Information).
The use of radio electronic equipment on board ships is subject to possession by radio operators of a certificate that guarantees that the level of competence is adequate for the service to be performed.
GOC – General Operator’s Certificate: required on SOLAS vessels operating in any of the sea areas
ROC – Restricted Operator’s Certificate: required on SOLAS vessels that operate only within sea area A1
LRC – Long Range Certificate: required on non-SOLAS vessels operating in any of the sea areas
SRC – Short Range Certificate: required on non-SOLAS vessels that operate only within sea area A1
THE GMDSS SEA AREAS
The GMDSS system defines four communication sea areas. Vessels must be fitted with adequate equipment according to the sea areas in which they operate.
SEA AREA A1
|An area within the range of at least one VHF Coast Station maintaining continuous DSC watch on Channel 70. This area extends up to 30-50 miles from the Coast Station.|
SEA AREA A2
|An area excluding Sea Area A1, within the radiotelephone coverage of at least one MF Coast Station maintaining continuous DSC watch on frequency 2187.5 kHz. This area extends about 150 miles from the Coast Station.|
SEA AREA A3
|An area excluding Sea Areas A1 and A2, within the coverage of an Inmarsat geostationary satellite. This area lies between 76 ° North and 76 ° South.|
SEA AREA A4
|An area outside Sea Areas A1, A2, A3. This is the Polar Regions north and south of about 76° of latitude.|