Relevant M-notices and documents: The Merchant Shipping (Radio Installations) regulations 1998, SOLAS.
This article was updated in September 2024 to reflect the 2024 SOLAS amendments.
The Global Maritime Distress and Safety System (GMDSS) is an international system that has been in place since 1999. It is legislated under SOLAS Chapter IV (Radiocommunication). The most important features to remember are that it allows for automated communication, both ship-ship and ship-shore, using Digital Selective Calling (DSC) technology.
We won’t go into detail regarding frequencies, programming and technical specifications of GMDSS equipment; that will be dealt with in a separate article. Another article will cover the correct steps to take when receiving a distress message.
The carriage requirements for GMDSS apply to ships over 300GT and passenger ships.
First off, what are the functional requirements under SOLAS Chapter IV? Don’t worry too much about this part, but it’s good to understand them to help make sense of the requirements that come after.
Every ship, while at sea, shall be capable:
except as provided in regulations 8.1.1 and 10.1.4.3, of transmitting ship-to-shore distress alerts by at least two separate and independent means, each using a different radiocommunication service;
of receiving shore-to-ship distress alerts;
of transmitting and receiving ship-to-ship distress alerts;
of transmitting and receiving search and rescue co-ordinating communications;
of transmitting and receiving on-scene communications;
of transmitting and, as required by regulation V/19.2.3.2, receiving signals for locating; **
of transmitting and receiving *** maritime safety information;
of transmitting and receiving general radio communications to and from shore-based radio systems or networks subject to regulation 15.8; and
of transmitting and receiving bridge-to-bridge communications.
It is best to structure our learning logically using the sea areas. These are defined in SOLAS Chapter IV:
A1. An area within the radiotelephone coverage of at least one VHF coast station keeping a continuous DSC watch.
A2. An area, excluding sea area A1, within the radiotelephone coverage of at least one MF coast station keeping a continuous DSC watch.
A3. An area excluding areas A1 and A2, within the range of the Recognized Mobile Satellite Service (RMSS) carried onboard.
A4. An area outside of A3. This means the polar regions.
To give an idea of the extent of these sea areas, the approximate ranges of different radio bands and coverage of RMSSs are:
VHF 40 miles
MF 150 miles
Geostationary satellites from 70 degrees North to 70 degrees South
Carriage requirements
The functional requirements given at the start of this article are met by the equipment outlined in SOLAS Chapter IV regulation 7 (radio equipment general). If asked where you’d check to find a list of the radio equipment carried on your ship, the answer is the Cargo Ship Safety Radio Certificate, form R or the Passenger Ship Safety Certificate, form P.
All ships over 300GT or passenger ships are required to carry:
NAVTEX receiver
A 9GHz SART (two SARTs if a passenger ship, or a cargo ship over 500GT, see also SOLAS regulation III/6.2.2). These can alternatively be AIS SARTs.
A 406MHz EPIRB (if trading exclusively in A1, this can be a VHF EPIRB)
VHF DSC set capable of receiving and transmitting on Ch 70 DSC and radiotelephony on Ch 16, 13 and 6.
Ships operating in sea area A1 must have, in addition to the above, one of the following:
A 406 MHz EPIRB
A VHF DSC EPIRB
A MF DSC system
A HF DSC system
A recognised* satellite ship earth station
Vessels operating in sea area A2 must meet the requirements for vessels operating in A1, and have:
A MF radio
A satellite EPIRB or a HF radio or a recognised* satellite ship earth station
Vessels operating in sea area A3 must meet the requirements for vessels operating in A1 and A2, and have:
A recognised* satellite ship station
A MF radio
A HF radio or a satellite EPIRB or an additional recognised* satellite ship earth station
Vessels operating in sea area A4 must meet the requirements for vessels operating in A1, A2 and A3 and have:
A satellite EPIRB
Some more pertinent information:
Anyone operating the GMDSS equipment (functionally, this means any deck officer) must hold a GMDSS General Operator Certificate (GOC). The GOC permits the holder to operate the radio installation onboard any vessel operating in any Sea Area, and to carry out routine tests. Holding a GoC is a pre-requisite for the issue of a MCA Deck CoC, and it must be re-validated every five years.
The minimum number of COG holders required on the vessel is states on the CSSR (form R) or on the PSSC (form P).
Forms R or P also include details on the methods used to ensure availability of radio facilities. These must be any one of these three if sailing in areas A1 or A2, or any two if sailing in A3 or A4:
Duplication of equipment
Shore-based maintenance (if selected, proof of a shore-based maintenance contract will be displayed on the bridge)
At-sea maintenance capability
*Be aware that, as of the Jan 2024 amendments to SOLAS, the GMDSS requirements have been updated to contain more generic requirements (rather than brand/system specific) and to remove some obsolete requirements. Formerly only INMARSAT was recognised, but now the Iridium network is approved, and widely acknowledged as being significantly better in high latitudes.
For more in-depth information on the GMDSS equipment, answering a distress call, maintenance of GMDSS equipment etc. check the other articles in this series by searching ‘GMDSS’.
MCAQs
An extremely common question at OOW level is ‘tell me about the GMDSS equipment on your last vessel’. You should be able to give a good answer to this from having assisted the 2/o with daily/weekly/monthly checks, but if you’re struggling to vocalise your knowledge, think about where these items are on the bridge. Imagine walking from outside (EPIRB), onto the bridge (SART by the door), then passing the SAT-C, the Navtex, the VHF and MF/MH radios etc. Describe it this way and you can’t go wrong.
What equipment do you need to carry in sea area A1/A2/A3/A4?
Where would you look to see a list of the radio equipment carried onboard?
Where would you find the number of GOC holders required on your vessel?
How long is a Cargo Ship Safety Radio Certificate valid for?