Ship equiped with VHF equipment in frequent rage of 156 - 174 MHz with DSC device must receive and transmit G2B type of emision on channel 70.
DSC is used for automatic call in alerts or exchange some other inforamtion on relation: coast-ship, ship-coast and ship-ship on VHF. That call can be directed to:
- all ships
- group of ships
- individual ship
- individual coast station
- group of coast station.
Ship equiped with DSC MF i HF equipment must receive and transmit F1B type of transmition according to the table (Radio Distress Communications, page 109).