HomeCalculatorsGMDSS - Sea Area Coverage Check

GMDSS - Sea Area Coverage Check

GMDSS sea-area (A1 / A2 / A3 / A4) determination from voyage distance from coast - drives radio-equipment carriage.

GMDSSSea areasSOLAS IV
Sea area
A2 (MF + A1)
Formula, assumptions, and limits

A1: VHF DSC coastal (25 nm). A2: MF DSC (150 nm). A3: INMARSAT coverage (70°N to 70°S). A4: Polar (no INMARSAT) - HF DSC mandatory + Iridium encouraged.

Symbol legend

SymbolMeaningUnitSource
GMDSS sea area - SOLAS IV Reg. 2