Global Maritime Distress and Safety System Sea Areas

A map of the UK indicating the 3 sea areas around the coast and the coast of nearby European countries. White pointers indicate Medium Frequency (MF) and Very High Frequency (VHF) coast radio stations. Red pointers indicate a Very High Frequency (VHF) coast radio station.

Sea area A1

The radiotelephone coverage of VHF coast stations in which continuous alerting by DSC is available.

This area relates to a vessel with an antenna 4m above sea level. Where the antenna is lower or it is a portable radio, the area is smaller.

Sea area A2

The radiotelephone coverage of MF coast stations in which continuous alerting by DSCis available.

Sea area A3

The coverage of Inmarsat geostationary satellites.