Subelement F: Maritime Safety Information (M.S.I.)— Topic :
Question 42F6
Element 7R (GMDSS-RO)What messages originate from registered information providers anywhere in the world and are broadcast to the appropriate ocean region via a LES?
Explanation
SafetyNETTM is an international satellite-based service integral to the Global Maritime Distress and Safety System (GMDSS). It disseminates Maritime Safety Information (MSI), which includes navigational warnings, meteorological warnings, and search and rescue information, to mariners worldwide. These messages originate from authorized information providers, are transmitted via Land Earth Stations (LES) to Inmarsat geostationary satellites, and then broadcast to specific ocean regions (NAVAREAs/METAREAs).
NAVTEX broadcasts (C) are incorrect because they use terrestrial MF (medium frequency) transmissions, not satellite links via LES, and have a more limited range. AMVER broadcasts (A) are a ship reporting system for search and rescue, not a general broadcast service for MSI. Urgency messages (B) are specific distress-related communications, usually initiated by vessels or coast stations, rather than routine MSI from general providers.
Related Questions
42F4 What system may be useful for messages, such as local storm warnings or a shore-to-ship Distress alert, for which it is inappropriate to alert all ships in the satellite coverage area?42F5 What services are available through Enhanced Group Calls?43G1 Adjusting the volume control has the following results:43G2 The Dual Watch (DW) function is used to:43G3 Setting the squelch control to just beyond the point where the background noise disappears results in: