GMDSS Communications System

Large commercial ships must have the Global Maritime Distress and Safety System fitted. The owners of smaller crafts should consider installing GMDSS with Digital Selective Calling (DSC).

Information in this section also explains the three types of 406 megahertz (MHz) beacons used to send a distress signal via satellites. Find out how to register or update a registration online.

Global Maritime Distress and Safety System

There are several uses for the GMDSS system. Seafarers use the maritime communications system for making:

  • Emergency and distress messages
  • Vessel-to-vessel routine communications
  • Vessel-to-shore routine communications

Commercial ships with more than 300 gross tonnage, and certain types of smaller craft, must have GMDSS equipment fitted.

Note: Most competing yachts in offshore yacht races must be GMDSS-equipped. The MSN 1963 performance specifications manual has further information on Merchant Shipping (Radio Installations) Regulations 1980.

Digital Selective Calling Explained

In fact, the owners of small leisure craft can choose whether to have GMDSS equipment fitted or not. Even so, the recommendation from HM Coastguard is for all pleasure craft to have GMDSS installed with DSC.

Digital Selective Calling (DSC) is a tone-signalling system. But, the main advantage of DSC facilities is the ability to include other important information, such as:

  • An identification number of the vessel
  • The purpose of the call
  • The position of your vessel
  • Which channel you want to use for communication

Registering 406 MHz Beacons

A 406 megahertz (MHz) beacon is able to send a distress signal via satellites. So, the crew can use this maritime communication system to alert search and rescue authorities of the ship’s location.

There are three different types of 406 megahertz (MHz) beacons:

  • Emergency Position Indicating Radio Beacons for ships and boats (e.g. EPIRB distress signal)
  • Emergency Locator Transmitters for aircraft (ELT)
  • Personal Locator Beacons for personal use (e.g. PLB safety alert)

Note: You would need to register your 406 MHz beacon with the coastguard and keep the registration accurate and up to date (details below).

Several events take place if you activate your beacon and the coastguard receives a distress signal. The search and rescue authorities would use the information on the register to contact you.

So, you should always:

  • Provide them with an emergency contact that they can call if the registered person is unreachable.
  • Notify the coastguard of any changes to the beacon or your vessel. This will help them to locate your vessel in an emergency situation.

How to Register or Update a Registration

There is a simple way to register or update a UK 406 MHz Beacon registration online (including EPIRBs, PLBs, or ELTs). There is no charge to update or register a 406 MHz Beacon in the United Kingdom.

The UK Beacon Registry can offer further help advice about the registration process:

The UK Beacon Registry
Email: [email protected]
Telephone: 013 2621 1569
Fax: 01326 319264
Find out call charge rates.

The Global Maritime Distress and Safety System in United Kingdom