Radiotelephony Communications (Distress, Urgency, Safety)
The exam tests your ability to compose and transmit the three priority messages correctly, to use the right frequency, and to control or close distress traffic. Radiotelephony remains the primary on-scene medium even in a DSC-based system.
Priority and formats
MAYDAY (spoken three times) is distress: grave and imminent danger requiring immediate assistance. The distress message contains: MAYDAY ×3, THIS IS, ship name/callsign/MMSI ×3, MAYDAY + name, position, nature of distress, assistance required, persons on board, other useful information, OVER. PAN PAN ×3 is urgency: a serious situation concerning safety but no immediate danger (medical evacuation, disabled vessel not in danger). SECURITE ×3 is safety: navigational or meteorological warnings.
Frequencies
VHF Ch 16 (156.8 MHz) for distress, urgency, safety and calling; Ch 70 is DSC only. MF 2182 kHz. HF 4125, 6215, 8291, 12290 and 16420 kHz. On-scene and intership safety work uses Ch 06 (156.300 MHz); bridge-to-bridge uses Ch 13; aeronautical SAR uses 121.5/123.1 MHz.
Control phrases
SEELONCE MAYDAY (imposed by the controlling station), SEELONCE FEENEE (distress traffic ended), PRU-DONCE (restricted working). MAYDAY RELAY is used to relay another station's distress.
Worked example
Engine-room fire, six persons on board, position 18°55'N 072°50'E, abandoning to liferaft. Transmit on Ch 16: "MAYDAY MAYDAY MAYDAY, THIS IS MV EXAMPLE, MV EXAMPLE, MV EXAMPLE, CALLSIGN XXXX, MMSI 419xxxxxx, MAYDAY MV EXAMPLE, POSITION 18°55'N 072°50'E, FIRE IN ENGINE ROOM, ABANDONING TO LIFERAFT, 6 PERSONS ON BOARD, OVER." Then follow the coast station's instruction to a working channel.
Traps
- Using MAYDAY for a medical case with no imminent danger (it is PAN PAN).
- Omitting position or persons on board.
- Saying OVER when the message is finished and no reply is wanted (use OUT).
- Testing or calling on 2182/Ch 16 instead of a working channel.