Module 5 - Routine Calls
Coast Stations and Public Correspondence
What you will learn
Follow the current routine DSC coast-station sequence and keep it separate from the conditional public-correspondence and AAIC service.
A coast station may provide safety, operational or public-correspondence services. Its published MMSI, acknowledgement and working-channel instruction control a routine DSC call; its name alone does not prove every service is offered.
MCA guidance says to call a DSC-equipped Coastguard or other coast station with an Individual DSC call using routine priority and the published MMSI. If the radio requests a working channel, enter the preferred channel according to the station procedure. After acknowledgement, accept the indicated working channel and wait for the coast station to call by voice.
Do not make the voice part on Channel 70 and do not transmit immediately over the coast station after acknowledgement. The acknowledgement has selected the route; moving and listening gives the station control of its working traffic. Verify the MMSI before transmitting because a familiar station name does not make an unverified number safe.
Public correspondence is a separate optional coast-station service. ITU List IV records stations and service classifications, while the SRC syllabus includes telephone-call and AAIC knowledge. Current availability, accounting authority, charges and call steps must come from the provider; never present an old syllabus example as a guaranteed live facility.
Worked example
The set acknowledges a routine coast-station DSC call and indicates Channel 73 for the voice exchange.
- 1Accept the acknowledgement and verify that the set has moved to Channel 73.
- 2Listen and wait for the coast station's voice call rather than transmitting over its workflow.
- 3When called, identify the vessel, give the concise routine purpose and follow any further instruction.
- 4Close cleanly and restore the required watch when the station releases the exchange.
Sense check: Channel 73 here is an example of an indicated channel, not a universal coast-station channel to memorise.
| Decision | Evidence to use | Unsafe shortcut |
|---|---|---|
| Which coast station? | Current published station identity and MMSI | Choosing a similar name from memory |
| Which voice channel? | The accepted DSC acknowledgement or station instruction | Speaking on Channel 70 |
| Who calls first by voice? | For the MCA routine coast-station sequence, wait for the station | Transmitting immediately after acknowledgement |
| Is telephone service available? | Current provider or official service information | Assuming every coast station offers public correspondence |
| Which AAIC? | The actual provider/accounting arrangement | Inventing or borrowing a code |
Make a verified routine DSC coast-station call
You need a routine operational conversation with a DSC-equipped coast station whose current MMSI is published in the passage information.
1. Verify and send
Confirm the MMSI from the current source, select Individual DSC routine priority and follow any preferred-channel prompt.
2. Accept and move
Read the acknowledgement, accept the indicated voice channel and confirm it on the display.
3. Wait for voice
Listen on the working channel for the coast station to call; then identify the vessel and exchange only the required traffic.
Sense check: The MMSI must be verified, the working channel must come from the accepted procedure and Channel 70 must carry no speech.
Common mistake or limitation
- Entering an unverified MMSI because the station name appears familiar.
- Speaking on Channel 70 or transmitting immediately instead of waiting on the acknowledged working channel.
- Assuming public correspondence and a usable AAIC arrangement exist without current provider evidence.
Recap
- Use Individual DSC routine priority and the coast station's verified published MMSI.
- Accept the indicated working channel, move and wait for the station's voice call.
- Treat public correspondence and AAIC as conditional provider services, not automatic coast-station features.
Optional quick check
Section 10 of 10
A routine DSC coast-station call is acknowledged with a working channel. What should happen next?
Sources and factual review
Reviewed 20 August 2026 - Compass Revision editorial review.
Continue studying Routine Calls
This public lesson is part of Revision Module 5. Full revision access adds the guided Learn, Practise and Test flow, flashcards and revision progress.