Digital Selective Calling (DSC)
A short digital 'call' used by ships and coast stations, including distress alerts, as part of the global maritime safety system.
ModeDigital Selective Calling
FamilyMaritime data
Audio exampleComing
What does it sound like?
Plate 10Maritime data
A brief, fast two-tone warble lasting a few seconds.
Field marksShort two-tone data burstsMaritime distress and calling channels
Who uses it?
Ships and coast stations worldwide.
Where and when can I hear it?
On shortwave and medium wave, 2187.5, 4207.5, 6312, 8414.5, 12577 and 16804.5 kHz; on VHF, channel 70 (156.525 MHz).
What do the decoded parts mean?
- Caller and called MMSI: The nine-digit identities of the calling and called stations.
- Category: Routine, safety, urgency or distress.
- Nature and position: For distress alerts: what happened and where.
Easily confused with
- AIS (ship positions), from the same family