The Global Maritime Distress and Safety System (GMDSS) provides critical communication channels for maritime safety. These frequencies are categorized for distress, routine communications, intership coordination, and satellite systems.
Dedicated to emergency and distress alerts, these frequencies ensure swift response in critical situations:
VHF Band: Channel 70 (DSC) and Channel 16 (Telephony Distress).
MF Band:
DSC: 2187.5 kHz
Telephony Distress: 2182 kHz
Telex: 2174.5 kHz
HF Bands:
HF4: 4207.5 kHz (DSC), 4125 kHz (Telephony), 4177.5 kHz (Telex).
HF6: 6312 kHz (DSC), 6215 kHz (Telephony), 6268 kHz (Telex).
HF8: 8414.5 kHz (DSC), 8291 kHz (Telephony), 8376.5 kHz (Telex).
HF12: 12577 kHz (DSC), 12290 kHz (Telephony), 12520 kHz (Telex).
HF16: 16804.5 kHz (DSC), 16420 kHz (Telephony), 16695 kHz (Telex).
These frequencies are used for non-emergency communication and operational coordination:
VHF Band: Channel 70 for both ship and shore, using G2B emission at 25 W.
MF Band:
Ship: 2177 kHz
Shore: 2189.5 kHz
Emission: F1B/J2B
Power: 400 W
HF Bands:
HF4: Ship 4219.5 kHz, Shore 4208 kHz.
HF6: Ship 6331 kHz, Shore 6312.5 kHz.
HF8: Ship 8436.5 kHz, Shore 8415 kHz.
HF12: Ship 12657 kHz, Shore 12577.5 kHz.
HF16: Ship 16903 kHz, Shore 16805 kHz.
HF18: Ship 19703.5 kHz, Shore 18898.5 kHz.
HF22: Ship 22444 kHz, Shore 22374.5 kHz.
HF26: Ship 26121 kHz, Shore 25208.5 kHz.
All HF routine frequencies use F1B/J2B emission at 1.5 kW.
VHF Channel 6: 156.3 MHz for intership communication.
Aviation Emergency Frequencies:
121.5 MHz and 123.1 MHz.
VHF Channel 13: 156.65 MHz for short-range coordination between vessels.
For direct communication and alerting between ships:
VHF Channels: 8, 10, 9, 72, 73, 69, 67, 77, 15, and 17.
MF/HF Bands:
Telephony: 2498, 4146, 6224, 8294, 12353, 16528, 18825, 22159 kHz.
Telex: 4203, 6301, 8397, 12560.5, 16785.5, 18893.5, 22352.5 kHz.
Inmarsat satellites provide global coverage for maritime safety:
AOR-E (Atlantic Ocean Region - East): Longitude 15.5° W.
TLX: 581
Phone: 871
Regional Station: Netherlands (Station 12).
AOR-W (Atlantic Ocean Region - West): Longitude 54° W.
TLX: 584
Phone: 874
Regional Station: Netherlands (Station 12).
IOR (Indian Ocean Region): Longitude 64.5° E.
TLX: 583
Phone: 873
Regional Station: Ata, Turkey (Station 10).
POR (Pacific Ocean Region): Longitude 178° E.
TLX: 582
Phone: 872
Regional Station: Kumsan, South Korea (Station 04).
These codes address specific maritime needs:
32: Medical Advices.
33: Technical Assistance.
38: Medical Assistance.
39: Maritime Assistance.
41: Meteo Warning.
42: Navigational Warning.
91: Test (Inmarsat-A).
The Admiralty List of Radio Signals (Vol. 5) outlines that the UK Coastguard MF DSC station transmits external "Test Safety" messages on 2187 kHz.
This comprehensive guide provides essential insights into the GMDSS frequency spectrum, vital for maintaining maritime safety worldwide.
