Digital Selective Calling (DSC)

A marine-radio system for sending digitally encoded alerts and calls to selected stations or groups.

Digital Selective Calling, or DSC, operates through compatible VHF and MF/HF equipment and forms part of the Global Maritime Distress and Safety System. A Maritime Mobile Service Identity identifies a vessel, coast station or group, allowing calls to be addressed without first establishing contact by voice.

A distress alert can include identity, position and the selected nature of distress when the radio is correctly configured and connected to a position source. DSC does not replace the required voice follow-up, listening watch or proper distress procedure, and accidental alerts must be cancelled using the recognised process.