Inmarsat satellite broadcast system delivering Maritime Safety Information to all vessels within a defined geographical area simultaneously.
Enhanced Group Call (EGC) is the broadcast capability of the Inmarsat-C satellite communication system that enables a shore authority to address simultaneously all vessels whose receivers are configured to receive messages within a specified geographical area. EGC is the technical mechanism underlying the SafetyNET and FleetNET services; SafetyNET is used for mandatory GMDSS Maritime Safety Information, whilst FleetNET is a commercial subscription service.
Under SOLAS Chapter IV, Regulation 7, ships operating in Sea Area A3 (between roughly 70°N and 70°S, covered by Inmarsat geostationary satellites) are required to maintain a continuous watch on EGC SafetyNET broadcasts. The system delivers navigational warnings, meteorological forecasts, distress relays, and shore-to-ship distress alerts formatted to a defined message priority scheme (distress, urgency, safety, routine).
EGC receivers automatically filter and print or display only those messages relevant to the vessel's current ocean region. The geographical filtering is achieved through the ocean region codes and area co-ordinates embedded in each broadcast header. IMO Performance Standards for EGC equipment are contained in IMO Resolution A.664(16) and associated amendments.