Inmarsat-C EGC broadcast service delivering Maritime Safety Information to vessels in ocean areas A3, used as the satellite component of the GMDSS MSI distribution system.
SafetyNET is the international maritime safety broadcast service operated through the Inmarsat-C Enhanced Group Call (EGC) system. It allows authorised shore authorities — including NAVAREA co-ordinators, national meteorological services, and Rescue Co-ordination Centres — to broadcast Maritime Safety Information simultaneously to all vessels whose Inmarsat-C Ship Earth Stations are within the relevant ocean region and have their EGC receivers active.
Messages are broadcast according to a defined priority hierarchy: distress priority carries the highest precedence, followed by urgency, safety, and routine categories. Geographical addressing enables transmissions to be targeted to specific ocean regions or rectangular sea areas, reducing irrelevant traffic aboard vessels outside the affected zone. SOLAS Chapter IV, Regulation 7 requires vessels in Sea Area A3 to maintain a continuous EGC watch on SafetyNET; complementary NAVTEX watch is required in coastal Sea Areas A1 and A2.
SafetyNET is distinct from Inmarsat's commercial FleetNET broadcast service, which is used for non-safety information on a subscription basis. Performance Standards for SafetyNET shipboard equipment form part of the Inmarsat-C SES Performance Standards in IMO Resolution A.807(19). Coverage extends between approximately 76°N and 76°S; beyond those latitudes, the Iridium GMDSS service provides alternative polar-region MSI delivery.