The Global Maritime Distress and Safety System (GMDSS) is an international safety system, which uses satellite and terrestrial technology and ship-board radio systems to prevent accidents from happening and to automatically alert the rescue authorities and nearby vessels quickly in an emergency.
Under the Safety of Life at Sea (SOLAS) Convention, cargo ships of 300 gross tonnage and upwards and all passenger ships on international voyages must be equipped with satellite and radio equipment that conforms to international standards.
In sea areas not covered by terrestrial radio communication systems, the GMDSS depends mostly on satellite communications for allowing seafarers to send distress alerts and receive safety information such as navigational warnings and weather forecasts.
Satellites play a vital role in distress, safety and search and rescue communications as part of the GMDSS. In 2022, over 900 distress alerts were transmitted and over 500,000 messages were broadcast to ships to advise them of weather forecasts and navigational issues.