GMDSS, Global Maritime Distress Safety System, in Italian "sistema mondiale di soccorso e sicurezza in mare".

What is GMDSS?

The GMDSS is a worldwide system that through the use of various radio equipment (on board and on land), allows better coordination of the management of emergencies at sea.

The GMDSS has its roots in the 1974 SOLAS Convention and its standards are developed by the IMO. Since 1999, all ships have had to adapt to this system.

Initially, only passenger ships of more than 300 gross tonnage and international routes were required to comply. Subsequently, passenger ships with national routes, fast ships, cargo ships, fishing boats with a length greater than or equal to 24 meters. and pleasure ships registered in international registers had to be adapted.

On-board equipment in the GMDSS system

The number of communication systems to be installed on board is strictly dependent on the maritime area in which the ship is to operate.

These areas are divided into 4 sectors:

  • Area A1, up to 20/30 miles from the coast (within range of VHF ground stations).
  • Area A2, area within the coverage range of at least one MF coast station (approximately 100 miles).
  • Area A3, area within the coverage of the Inmarsat satellite system which excludes only the polar regions (beyond the 70th parallel North and South).
  • Area A4, meaning the polar areas (i.e. areas excluded from areas A1, A2 and A3).

Basic equipment (equipment common to all operational areas):

  • N.2 VHF / DSC Class A
  • N.2 Portable VHF - N.3 if greater than 500 GRT
  • N.1 AIS Transponder Class A
  • N.1 NAVTEX receiver or an Inmarsat EGC system receiver for areas not covered by the NAVTEX service.
  • N.1 EPIRB (406 Mhz)
  • N.1 SART (or AIS-SART) - N.2 if greater than 500 GRT

Extra equipment for the A2 area:

  • N.1 MF/DSC

Extra equipment for area A3:

  • N.2 Inmarsat C + N.1 MF/DSC, or
  • N.1 Inmarsat C + N.1 MF/HF/DSC, or
  • N.2 Inmarsat A (at least one with EGC) + N.1 MF/DSC, or
  • N.1 Inmarsat A + N.1 Inmarsat C + N.1 MF/DSC, or
  • N.1 Inmarsat A with EGC + N.1 MF/HF/DSC, or
  • N.2 MF/HF/DSC

Extra equipment for the A4 area:

  • N.2 MF/HF/DSC