MSI

Maritime Safety Information (MSI) is the collective term for a range of safety-critical broadcasts disseminated to vessels at sea under the GMDSS framework. As defined by SOLAS Chapter IV, Regulation 2, MSI encompasses navigational warnings, meteorological warnings and forecasts, distress alerts, and other urgent safety-related messages including piracy and armed robbery advisories and SAR co-ordination information. MSI is disseminated through two principal GMDSS systems: NAVTEX for coastal waters in Sea Areas A1 and A2, and the Inmarsat-C SafetyNET EGC service for ocean areas in Sea Area A3. In Sea Area A4 polar waters, NAVTEX may be supplemented by HF radio services, Iridium GMDSS, or other recognised means. SOLAS Chapter V, Regulation 4 requires contracting governments to arrange meteorological services, whilst Chapter IV, Regulation 7 requires ships to maintain a continuous watch on appropriate MSI services. MSI broadcasts are co-ordinated internationally through the IMO/IHO World-Wide Navigational Warning Service (WWNWS), the World Meteorological Organization (WMO) for meteorological products, and regional co-ordination bodies. The integrity and timeliness of MSI reception is essential to the safety of navigation, and ships are required to obtain an up-to-date broadcast before departure and to maintain reception throughout the voyage.