Which communication system covers SEA AREA A1 in the United States?

• A. Rescue 21 System
• B. GMDSS
• C. NAVTEX
• D. SITOR

Answer: (A)

Sea Area A1 is the near-shore VHF coverage area defined for GMDSS, where distress communications can occur via line-of-sight VHF between ships and shore stations. In the United States, Rescue 21 is the Coast Guard’s coastal VHF communications system built to provide continuous, near-shore coverage for search-and-rescue operations, handling voice and digital calls (DSC) to and from shore stations and vessels. Because it is specifically implemented to deliver that A1-level near-shore coverage across U.S. waters, it is the system that covers Sea Area A1 in the United States. Global GMDSS also includes A1, but Rescue 21 is the U.S.-specific system ensuring the required A1 near-shore reach, while NAVTEX and SITOR are separate components used for particular safety broadcasts and data transmissions, not the overall A1 coverage system.