Sea Area A1 in GMDSS is defined as what?

Sea Area A1 in GMDSS is defined as what?

• A. VHF-FM range out to 20 nautical miles offshore
• B. MF/HF long-range coverage
• C. Satellite coverage only
• D. Inland waterway coverage only

Answer: (A)

Sea Area A1 is the zone where a vessel is within reach of coastal VHF radiotelephone networks. VHF communications are line-of-sight, so the practical coverage from shore-based VHF transmitters typically extends up to about 20 nautical miles offshore. This allows safety and distress communications to be handled via VHF channels close to the coast. Beyond this VHF range, other systems take over: MF/HF long-range coverage for Sea Area A2, satellite coverage for Sea Area A3, and polar regions where satellite coverage isn’t available for Sea Area A4. So the description of VHF-FM range out to about 20 nautical miles offshore matches Sea Area A1.

Sea Area A1 is the zone where a vessel is within reach of coastal VHF radiotelephone networks. VHF communications are line-of-sight, so the practical coverage from shore-based VHF transmitters typically extends up to about 20 nautical miles offshore. This allows safety and distress communications to be handled via VHF channels close to the coast. Beyond this VHF range, other systems take over: MF/HF long-range coverage for Sea Area A2, satellite coverage for Sea Area A3, and polar regions where satellite coverage isn’t available for Sea Area A4. So the description of VHF-FM range out to about 20 nautical miles offshore matches Sea Area A1.