The global maritime distress and safety system was implemented in 1999 by amendments to the Safety of Life at Sea (SOLAS) convention. GMDSS is an international radio safety system that automates and improves the efficiency of radio watch keeping and distress communication for the world shipping industry.
The idea is to link Search and Rescue (SAR) authorities ashore with vessels close to vessel in distress as is illustrated by Figure 3.19.
Figure 18 Illustration of the function of Search and Rescue areas and the radio safety system.
Source : http://www.irisdsc.com.ar/en/gmdss
Table 3 defines Safety and rescue areas. .
, for the Inmarsat link in the table use http://www.inmarsat.com/)