- You are using VHF or MF procedures (not HF - see below).
If you need to send a DSC Distress Relay to a Coast Station/
MRCC: - Establish from ALRS Volume 5 (or other suitable publication) the
MMSI of the Coast Station/MRCC concerned. - Use the 'individual Distress Relay' programme on your DSC
Controller to initiate the relay (not the 'All Stations' programme). - Move to the voice channel associated with your DSC Alerting
frequency after receiving a DSC Acknowledgement from the Coast
Station/MRCC called, to pass your voice 'Mayday Relay' call
and message.
Summary of Distress Acknowledgement/Distress Relay (HF)
Rules
Do not send a DSC Distress Acknowledgement, or a voice
acknowledgement, on HF, to another vessel:- HF DSC Alerts from ships are intended for reception by Coast
Stations. The nature of sky-wave propagation means that a large
number of other vessels may also receive an HF DSC Distress
Alert, but may not be at a good 'skip distance' to receive the Coast
Station reply. Sending DSC/voice Acknowledgements by HF can
result in the alerting/working frequency being overwhelmed by
Signals, causing the casualty to lose contact with the Coast Station.
Never send an ~ll Stations' DSC Distress Relay on HF: - Any ship you contact by HF will be hundreds or thousands of
miles from your position (and also, for most of them, from the
casualty). - DSC Distress Relays (on HF) should only be used to alert a Coast
Station, never to alert other ships. - Establish from ALRS Volume 5 (or other suitable publication) the
MMSI of a suitable Coast Station/MRCC to receive the relay. - Use the 'individual Distress Relay' programme on your DSC
Controller to initiate the relay (not the 'All Stations' programme). - Move to the voice channel paired with your DSC Alerting frequency,
after receiving a DSC Acknowledgement from the Coast Station/
MRCC called, to pass your voice 'Mayday Relay' call and message.
MARINE COMMUNICATIONS 101