GMDSS Radio Signals Radio signals are transmitted as electromagnetic radiation and occupy the frequency range 3 kHz ~ 300 GHz. The radiofrequency range is divided into a number of bands. In the GMDSS system both terrestrial and satellite methods of communications are interlocked in order to provide an extremely reliable scheme to alert rescue authorities in the event of a vessel being in distress.Frequencies in the MF, HF and VHF bands are used for terrestrial communications via Coast Radio Stations (CRS). Frequencies in the SHF bands are used for satellite communications. It's important … [Read more...]
EPIRB – Emergency Position indicating Radio Beacon
An Emergency Position Indicating Radio Beacon or EPIRB is a safety device carried by a vessel to alert search and rescue services and allow them to quickly locate you in the event of an emergency. It does this by transmitting a coded message on the 406 MHz distress frequency via satellite and earth stations to the nearest rescue coordination centre.An EPIRB usually works on 406/121.5 MHZ and can be manually or automatically activated and some models are also water activated. 121.5/243 MHz EPIRBs The International Cospas-Sarsat System ceased satellite processing of 121.5/243 MHz beacons … [Read more...]
GMDSS Radio Equipment Requirements on Ship as per SOLAS
The GMDSS radio equipment requirements are categorized as following:General Sea area A1 Sea areas A1 and A2 Sea areas A1, A2 and A3 Sea areas A1, A2, A3 and A4 Radio equipment: GeneralEvery ship shall be provided with:VHF radio capable of transmitting and receiving:-DSC on the frequency 156.525 MHz (channel 70) and maintain a continuous watch on the same -Radiotelephony on the frequencies 156.300 MHz (channel 6), 156.650 MHz (channel 13) and 156.800 MHz (channel 16);A search and rescue locating device (SART) capable of operating either … [Read more...]
ANNEX IV – Distress Signals
1. Need of Assistance The following signals, used or exhibited either together or separately, indicate distress and need of assistance:(a) a gun or other explosive signal fired at intervals of about a minute;(b) a continuous sounding with any fog-signalling apparatus;(c) rockets or shells, throwing red stars fired one at a time at short intervals;(d) a signal made by any signalling method consisting of the group ... --- ... (SOS) in the Morse Code;(e) a signal sent by radiotelephony consisting of the spoken word "Mayday";(f) the International Code Signal of distress … [Read more...]