GMDSS – Definition and Pronunciation
What is GMDSS?
The Global Maritime Distress and Safety System: the Inmarsat-A/B and C
systems are the only Inmarsat networks included in the GMDSS by the IMO International
Maritime Organisation.
Examples of GMDSS
Distress and safety communications in the GMDSS rely on the use of radio communications through terrestrial MF, HF and VHF links and through satellites.
From “GMDSS Distress and Safety Communications”.
The GMDSS will apply to call cargo ships of 300 gross tonnage and above, and to all passenger ships, regardless of size, on international voyages.
From “GMDSS carriage requirements and basic provisions”.
However, because of the lack of space on board many modern ships, most GMDSS fittings use vertical whip antennas for MF/HF transmissions. For example, the main HF transceiver may use an 8 m whip, the 2 128 KHz watchkeeping receiver may use a 4 m whip and the NAVTEX receiver may use a 1 m whip. A separate 6 m whip is commonly used for the MF/HF DSC receiver.
From “The Structure, Functions and Details of Professional Marine Radio Communication”.