Digital Selective Calling (DSC) on VHF and MF or MF/HF
for automatic monitoring of distress channels, transmitting and receiving distress alerts, as well as general radio communications. Radio equipment must be connected to GPS to automatically take over ship´s position.
406 MHz Emergency Position Indicating Radio Beacon (EPIRB)
for global detection and for location by means of the Doppler effect through COSPAS/SARSAT system.
Search And Rescue Transponder (SART)
to help locate of survivors of distressed vessels. SARTs transmit in response to received radar signals. The trasmitted signals are displayed on radar screens as a series of dots with range and bearing information to accurately indicate the position of the ship in distress.
Satellite Communications and Distress Alerting Shore-to-Ship
with Inmarsat A, B or C terminals through Inmarsat network which provides global communications and distress alerting with exception of polar regions. Inmarsat SESs as part of the GMDSS must be connected to GPS to automatically take over ship´s position.
Maritime Safety Information (MSI)
comprise distress alerts, SAR information, navigational and weather warnings, as well as forecasts, can be received in three different ways in GMDSS:
- NAVTEX receivers are fully automatic and receive broadcasts in coastal regions up to 300 nautical miles offshore
- Inmarsat-C terminals receive Enhanced Group Call - SafetyNET (EGC) broadcasts for areas outside NAVTEX coverage.
- HF Narrow Band Direct Printing (NBDP) receivers can be used where service is available as an alternate to EGC