Yachtmaster revision module 18 of 20

VHF

Signals & Communications

Distress, urgency, safety calls, DSC/VHF procedure, visual signals, flag signals, Morse, and harbour traffic signals.

MAYDAY, PAN PAN, and Securite call selectionDSC distress alerts, MMSI, and voice follow-up

18 guided lessons · 24 practice questions · 25 flashcards

3 outcomes · self-guided revision
  • Explain distress, urgency, safety calls, DSC/VHF procedure, visual signals, flag signals, Morse, and harbour traffic signals.
  • Apply MAYDAY, PAN PAN, and Securite call selection to a realistic onboard situation.
  • Recall the core check: mAYDAY: grave and imminent danger.

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Lesson summaries

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Distress, Urgency and Safety Calls

A Yachtmaster candidate must be able to choose the right level of radio call quickly. MAYDAY is for grave and imminent danger to a vessel or person. PAN-PAN is for urgency, where help or...

  • MAYDAY: grave and imminent danger
  • PAN-PAN: urgent situation, not immediate danger to life
Read the full lesson: Distress, Urgency and Safety Calls

DSC Distress Alerts

Digital Selective Calling (DSC) sends an electronic distress alert from the VHF set. A DSC distress alert normally includes the vessel MMSI, position if the radio is connected to GNSS, ti...

  • DSC sends an electronic distress alert
  • MMSI identifies the vessel
Read the full lesson: DSC Distress Alerts

MAYDAY Voice Format

A clear voice MAYDAY follows a predictable structure: MAYDAY repeated three times, vessel name repeated three times, call sign or MMSI if available, position, nature of distress, assistan...

  • Say MAYDAY three times at the start
  • Give vessel identity clearly
Read the full lesson: MAYDAY Voice Format

PAN-PAN and Securite

PAN-PAN is used for urgent situations such as engine failure near a lee shore, a serious but stable medical problem, or a vessel disabled but not in grave and imminent danger. For the MCA...

  • PAN-PAN: urgent help or advice needed
  • Securite: safety information for other vessels
Read the full lesson: PAN-PAN and Securite

Relay and Acknowledgement

If you hear a distress call and no coastguard or other station responds, you may need to relay the distress. A MAYDAY RELAY passes on the distress details so that rescue authorities recei...

  • Use MAYDAY RELAY if a distress call is not being answered
  • Do not interrupt an active rescue exchange unnecessarily
Read the full lesson: Relay and Acknowledgement

Visual Distress Signals

Visual distress signals support radio and electronic alerting. Red parachute rockets are for long-range night or poor-visibility alerting. Red hand flares help rescuers pinpoint the vesse...

  • Red parachute rocket: long-range distress
  • Red hand flare: close-range distress location
Read the full lesson: Visual Distress Signals

International Code of Signals

The International Code of Signals provides a standard set of flags, pennants, and meanings. Yachtmasters do not need to memorise the whole code, but they should recognise common safety fl...

  • A / Alpha: diver down, keep clear and slow
  • B / Bravo: dangerous goods
Read the full lesson: International Code of Signals

Morse, Sound and Light Signals

SOS in Morse is three short, three long, three short. It can be sent by light, sound, or any other signalling method. A safe water mark often uses Morse A, which is dot dash. A Yachtmaste...

  • SOS: three short, three long, three short
  • Morse A: dot dash, commonly used by safe water marks
Read the full lesson: Morse, Sound and Light Signals

Harbour and Traffic Signals

Harbour entrances, locks, bridges, and traffic-controlled channels may display lights, boards, flags, or VHF instructions. The exact system is local, so the skipper must check the almanac...

  • Check local traffic signals before arrival
  • Use the harbour VHF working channel when required
Read the full lesson: Harbour and Traffic Signals

Radio Discipline

Good VHF discipline is part of seamanship. Listen before transmitting, use low power when range allows, keep calls short, and move routine traffic to a working channel. Channel 16 must be...

  • Listen before transmitting
  • Use low power for local calls where practical
Read the full lesson: Radio Discipline

Complete DSC Distress Workflow

When grave and imminent danger requires immediate assistance, lift the cover, select the nature of distress if time permits, and press and hold the distress control until the set confirms...

  • Press and hold the distress control until the alert is confirmed sent
  • After acknowledgement or about 15 seconds, send the voice MAYDAY on Channel 16
Read the full lesson: Complete DSC Distress Workflow

Choosing Priority and Escalating Early

Priority is determined by the real condition, not by whether the skipper feels embarrassed about calling. Flooding that is being contained may become grave and imminent if pumps are losin...

  • Choose priority from danger, trend, time, people, and remaining controls
  • MAYDAY is not postponed when grave and imminent danger exists
Read the full lesson: Choosing Priority and Escalating Early

Coverage, Antennas and a Communications Failure Plan

VHF is principally line of sight. Antenna height, terrain, vessel structure, sea state, transmitter power, cabling, and the receiving station affect range. A masthead fixed set usually re...

  • VHF range depends strongly on antenna height and line of sight
  • A handheld at deck level normally has less range than a masthead fixed set
Read the full lesson: Coverage, Antennas and a Communications Failure Plan

Channel 70, Channel 16 and Working Channels

Channel 70 is reserved for DSC signalling and must not be used for voice. Channel 16 carries distress, urgency, very brief safety communications, and initial calling where the procedure r...

  • Channel 70 is DSC data only, never voice
  • Keep Channel 16 clear and move routine traffic to a working channel
Read the full lesson: Channel 70, Channel 16 and Working Channels

Distress Reception, Relay and Safe Assistance

On receiving a DSC distress alert, stop transmissions that may interfere and maintain a listening watch on Channel 16. Record the identity, position, time, nature of distress, and control...

  • On receipt, stop interference, listen on Channel 16, and write the facts
  • Allow the Coastguard or appropriate coast station to coordinate
Read the full lesson: Distress Reception, Relay and Safe Assistance

Position, Phonetics, Read-back and Radio Log

Prepare position before the call. Latitude and longitude must include degrees, minutes, decimals if used, and North or South, East or West; give the time and datum if relevant. Alternativ...

  • Write and cross-check the position before transmitting when time permits
  • Include complete coordinate directions and a clear time basis
Read the full lesson: Position, Phonetics, Read-back and Radio Log

Yachtmaster Offshore Standard

Signals & Communications at Yachtmaster level is not just recall. The answer has to show command judgement, evidence quality, margin, and a fallback if the first plan stops being safe.

  • State the evidence you trust and the evidence you distrust.
  • Name the margin that makes the plan defensible.
Read the full lesson: Yachtmaster Offshore Standard

Advanced Scenario Check

Decision pressure: A slow or unclear communication plan can turn a manageable incident into distress.

  • Apply MAYDAY, PAN PAN, and Securite call selection to a changed real-world situation.
  • Separate fact, estimate, and assumption.
Read the full lesson: Advanced Scenario Check

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