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NZ MVOC (VHF Radio) study materials
NZ MVOC (VHF Radio) study resources

NZ MVOC (VHF Radio): Marine VHF Operating Procedures and Distress, Urgency and Safety Traffic

NZ MVOC (VHF Radio) · Work through your exam, one topic at a time.

All guide sections

Marine VHF Operating Procedures and Distress, Urgency and Safety Traffic

What this domain tests

This domain tests whether you can run a disciplined listening watch and use the three priority levels of maritime radio traffic correctly - the routine procedural core that the rest of the certificate builds on.

Watchkeeping and identification

  • Listen before every transmission. If Ch 16 is busy, wait.
  • Identify with vessel name and callsign at the start and end of each exchange. New Zealand ship stations hold a callsign beginning with ZM.
  • Ch 16 (156.800 MHz) is the calling, distress and safety channel. Make contact there, then move to a working channel (Ch 6, 67 or an assigned port channel) and free Ch 16.
  • Observe the silence periods (minutes 00–03 and 30–33 past each hour) on Ch 16 unless you are handling distress traffic.
  • Log distress, urgency and safety traffic with times.

Priority levels and their wording

  • MAYDAY (spoken three times): grave and imminent danger, life at risk. Highest priority.
  • PAN PAN (three times): urgency - a vessel or person is in difficulty but not in immediate grave danger (breakdown, injury, drifting towards a lee shore).
  • SECURITE (three times): safety - navigation hazards, gale warnings, objects adrift.
  • MAYDAY RELAY: used when you hear an unacknowledged distress and no coast station has replied, or when a station that cannot transmit asks you to relay.

Worked example

A Coastguard unit answers your Ch 16 call and offers a radio check. Reasoning: a radio check is routine traffic, so do not tie up Ch 16 with signal reports. Propose a working channel, switch, give a short call ("loud and clear"), confirm the switch back, and end with your callsign and "OUT". If the check is poor, test the antenna connection and power setting before assuming the set has failed.

Traps that cost marks

  • "Over and out" - use OVER when a reply is expected, OUT to close.
  • Sending MAYDAY for a tow or fuel shortage; that is PAN PAN at most.
  • Omitting position, persons on board, or the nature of the distress.
  • Voice on Ch 70 (DSC only) or chatting on Ch 16.