Global Maritime Distress Safety System (GMDSS)

GMDSS is the set of technologies that implements the SOLAS treaty.  All vessels over 300 tons displacement, as well as passenger vessels of any size, must comply with GMDSS requirements. Smaller vessels are wise to do so, in the interest of safety.

Critical components of GMDSS

Radio equipped with Digital Selective Calling

EPIRB beacon

NAVTEX navigational and weather receiver

Satellite systems operated by the Inmarsat, under contract to the International Maritime Satellite Organization (IMSO), are also important elements of the GMDSS.  Three types of Inmarsat ship earth station terminals are recognized by the GMDSS:

Inmarsat B

Inmarsat C

Inmarsat F77