GMDSS Sailing area A1 is valid for commercial vessels of 300GT and above engaged in international voyages and covers the area within VHF coastal station range, generally 20-30NM offshore. Equipment fitted needs to be either 1) duplicated or 2) maintained on-board by a certified radio/electronic officer with spares and manuals or 3) supported by a shore-based-maintenance contract (SBMCC). Below package solutions are based upon duplication.