The Global Maritime Distress and Safety System

The Global Maritime Distress and Safety System (GMDSS) is a maritime communications system used for:

  • emergency and distress messages
  • vessel-to-vessel routine communications
  • vessel-to-shore routine communications

If you own commercial ships with over 300 gross tonnage, or certain smaller craft, fit them with GMDSS equipment.

Most offshore yacht races also now insist that competing yachts are GMDSS-equipped.

Read the Merchant Shipping (Radio Installations) Regulations for more information on who has to fit GMDSS.

Digital Selective Calling (DSC) for pleasure craft

It’s voluntary for small leisure craft to have GMDSS, but HM Coastguard strongly recommends that pleasure craft install GMDSS with DSC.

DSC is a tone-signalling system with the ability to include other information like:

  • a vessel’s identification number
  • the purpose of the call
  • your position
  • the channel you want to speak on