Radio Regulations, Licensing, and Frequency Management
This domain checks that you know the legal framework behind the equipment: who licenses the ship, who certifies the operator, and which transmissions are prohibited.
Certificates and licences
- The GOC is the operator certificate required for GMDSS radio duties on SOLAS ships; the ROC is the restricted certificate for VHF-only operation.
- The ship station licence is issued by the administration; in India this is administered by the WPC wing of the Ministry of Communications, which also assigns the MMSI.
- The EPIRB is registered separately with the national registry, and the details must match the licence and MMSI.
- The radio log records distress, urgency and safety traffic, tests, watches, battery checks and equipment failures.
Frequency discipline
Frequencies are allocated by the ITU Radio Regulations. Distress and safety frequencies (Ch 16, 2182 kHz, 4125/6215/8291/12290/16420 kHz, Ch 70, 406 MHz, 9 GHz) must not be used for routine or test traffic. Ch 70 is DSC only; 121.5 MHz is aeronautical emergency and is not a ship calling channel. Emissions must be on the assigned frequency, with the correct class (G3E for VHF FM voice, J3E for SSB suppressed carrier, F1B for NBDP) and within tolerance.
Operator obligations
Priority of distress traffic; secrecy of communications; correct identification by callsign and MMSI; no harmful interference; no unauthorised transmissions; compliance with the ship's licence conditions.
Worked example
A ship changes owner and name. The new MMSI and callsign must be entered in the DSC and AIS, the ship station licence amended, the EPIRB registration updated, and the radio log annotated. Reasoning: an alert from an unregistered or mismatched beacon delays RCC verification and can send SAR assets to the wrong contact.
Traps
- Treating the MMSI as the callsign; they are different identifiers.
- Using 121.5 MHz or Ch 70 for radio checks.
- Assuming the equipment manufacturer issues the ship licence.
- Omitting the radio log entries that an inspector will ask for.