GMDSS - Global Maritime Distress and Safety System

The Global Maritime Distress and Safety System GMDSS is an internationally recognized, automated ship-to-shore distress and radio communication safety system using satellites and digital selective calling technology on MF, HF and VHF and replacing the previous ship-to-ship safety system, which relies on a manual Morse code system on 500 kHz and voice radiotelephony on Channel 16 and 2182 kHz.

Which ships are affected?

The international GMDSS regulations apply to "compulsory" ships, including:

  • Cargo ships of 300+ GT and over when traveling on international voyages or in the open sea
  • All passenger ships carrying more than 12 passengers when traveling on international voyages or in the open sea