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NZ MVOC (VHF Radio) study materials
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NZ MVOC (VHF Radio) practice questions

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Question 1Marine VHF radio operating procedures and distress, urgency and safety communications

On a New Zealand marine VHF set, which channel is designated for digital selective calling (DSC) distress and safety alerts?

  1. Channel 70 Correct answer.
  2. Channel 06
  3. Channel 13
  4. Channel 16

Explanation

Channel 70 is reserved internationally for DSC and must never be used for voice transmissions, because digital alerts would be corrupted by speech. Channel 16 remains the voice distress and calling channel, and Channel 06 is the inter-ship safety channel.

Question 2Marine VHF radio operating procedures and distress, urgency and safety communications

Which spoken phrase correctly signals that a transmission concerns a very urgent message about the safety of a vessel or person?

  1. Silence Mayday
  2. Pan Pan Correct answer.
  3. Mayday
  4. Securite

Explanation

Pan Pan, spoken three times, precedes an urgency message concerning the safety of a vessel or person but not an immediate grave danger. Mayday is reserved for grave and imminent danger, and Securite introduces safety information such as navigational warnings.

Question 3Marine VHF radio operating procedures and distress, urgency and safety communications

What is the correct spoken form of the distress call on VHF?

  1. Mayday Mayday Mayday, this is vessel name and callsign Correct answer.
  2. Mayday, this is, Mayday, this is, vessel name and callsign
  3. Mayday, vessel name, over
  4. Pan Pan, this is vessel name and callsign

Explanation

The distress call consists of Mayday spoken three times followed by the words this is and the vessel's name and callsign. Repeating Mayday three times makes the alert unmistakable to all stations listening, including coast stations.

Question 4Marine VHF radio operating procedures and distress, urgency and safety communications

Which channel should a vessel use for routine ship-to-ship communications in New Zealand waters?

  1. Channel 16
  2. Channel 06 Correct answer.
  3. Channel 15
  4. Channel 70

Explanation

Channel 06 is the designated inter-ship channel for routine ship-to-ship working, keeping Channel 16 clear for distress, urgency, safety and calling. After initial contact on 16, stations should move to a working channel such as 06.

Question 5Marine VHF radio operating procedures and distress, urgency and safety communications

A vessel hears a Mayday relay being transmitted by a coast station. What does the relay indicate?

  1. The coast station is itself in grave and imminent danger
  2. A routine safety warning is being broadcast
  3. A third station is in distress and the coast station is passing on the alert Correct answer.
  4. A test transmission is being conducted

Explanation

A Mayday relay is used when a station other than the one in distress transmits the distress alert on behalf of that vessel, for example when the casualty's own signal was weak or not heard. The relaying station prefixes the message with Mayday Relay.

Question 6Marine VHF radio operating procedures and distress, urgency and safety communications

How is the urgency signal spoken on VHF when opening a Pan Pan message?

  1. Four times, followed by the word over
  2. Once, followed by the vessel name
  3. Three times, followed by all stations and the vessel identification Correct answer.
  4. Twice, followed by all stations

Explanation

The urgency signal consists of the words Pan Pan spoken three times, followed by all stations (or a specific station), then this is and the vessel's name and callsign. The repetition ensures the priority level is clearly recognised.

Question 7Marine VHF radio operating procedures and distress, urgency and safety communications

Which statement about listening watch on Channel 16 is correct for a vessel fitted with VHF in New Zealand?

  1. Channel 16 need only be monitored during daylight hours
  2. Channel 16 is monitored only when a distress is known to be in progress
  3. A continuous watch on Channel 16 is required while the radio is operating and the vessel is at sea Correct answer.
  4. Channel 16 may be switched off whenever the vessel is moving

Explanation

Vessels fitted with VHF are expected to maintain a continuous listening watch on the distress and calling channel whenever the radio is in operation at sea. This ensures distress, urgency and safety traffic can be received promptly.

Question 8Marine VHF radio operating procedures and distress, urgency and safety communications

What does the spoken word over indicate at the end of a VHF transmission?

  1. The station has finished speaking and a reply is expected Correct answer.
  2. The station is changing channel
  3. The station is in distress
  4. The station has finished and expects no reply

Explanation

Over signals that the transmitting station has finished its turn and is inviting a reply from the other station. By contrast, out indicates the end of the exchange with no reply expected.

Question 9Marine VHF radio operating procedures and distress, urgency and safety communications

A vessel has struck a submerged object and is taking on water but is not in immediate danger of sinking. Which signal best matches this situation?

  1. No signal, because the vessel is still afloat
  2. Securite, because it concerns navigation
  3. Mayday, because water is entering the hull
  4. Pan Pan, because the vessel is in urgent need of assistance but not in grave and imminent danger Correct answer.

Explanation

Urgency applies where there is a serious situation concerning the safety of a vessel or person that does not yet meet the grave and imminent danger test for distress. A vessel taking water but not at immediate risk of sinking is a classic Pan Pan case, allowing authorities to prepare assistance.

Question 10Marine VHF radio operating procedures and distress, urgency and safety communications

What is the correct order of information in a distress message after the distress call?

  1. Position, vessel name, number of persons on board, nature of distress, assistance required
  2. Vessel name, position, nature of distress, assistance required, number of persons on board, other information Correct answer.
  3. Number of persons on board, nature of distress, position, vessel name, assistance required
  4. Nature of distress, vessel name, position, assistance required, number of persons on board

Explanation

The distress message follows the sequence: Mayday, this is, vessel name and callsign, position, nature of distress, assistance required, number of persons on board, and any other useful information such as vessel type. This standard order lets rescuers capture the most critical facts quickly.

Question 11Marine VHF radio operating procedures and distress, urgency and safety communications

A vessel is asked to impose silence during a distress incident. What is the correct phrase and who may impose it?

  1. Silence Fini, imposed by any vessel in the area
  2. Silence Pan Pan, imposed by the casualty vessel only
  3. Silence Mayday, imposed by any station that hears the distress
  4. Silence Mayday, imposed by the station controlling the distress traffic or a coast station Correct answer.

Explanation

Silence Mayday is used to impose radio silence on stations interfering with distress traffic, and it is issued by the station controlling the traffic, typically a coast station or the on-scene coordinator. Once the traffic is complete, Silence Fini lifts the restriction.

Question 12Marine VHF radio operating procedures and distress, urgency and safety communications

When transmitting a DSC distress alert, what should follow once the alert is sent?

  1. A request for a radio check on Channel 70
  2. Nothing further; the DSC alert replaces all voice communication
  3. A voice Mayday call and message on Channel 16 Correct answer.
  4. A Securite broadcast on Channel 06

Explanation

A DSC distress alert should be followed by a voice Mayday call and message on Channel 16, which gives listening stations the details of the emergency. The DSC alert alone carries limited information, so the voice follow-up is essential.

Question 13Marine VHF radio operating procedures and distress, urgency and safety communications

A vessel receives no reply after transmitting a DSC distress alert. What is the recommended action?

  1. Repeat the DSC distress alert after a short interval, then send a voice Mayday on Channel 16 Correct answer.
  2. Transmit a Mayday relay on behalf of another vessel
  3. Switch off the radio and wait for rescue
  4. Change to Channel 06 and broadcast a Securite message

Explanation

If no acknowledgement is received, the vessel should repeat the DSC distress alert after a suitable interval and also transmit a voice Mayday call and message on Channel 16 so that any listening station can respond. Persistence improves the chance of detection.

Question 14Marine VHF radio operating procedures and distress, urgency and safety communications

What is the purpose of the Securite signal on VHF?

  1. To request urgent medical advice
  2. To indicate a vessel is sinking
  3. To announce a safety message such as a navigational or weather warning Correct answer.
  4. To test the radio installation

Explanation

Securite, spoken three times, introduces a safety message concerning navigation or meteorological warnings that affects the safety of vessels. It has lower priority than distress and urgency but still warrants attention from all stations.

Question 15Marine VHF radio operating procedures and distress, urgency and safety communications

Which practice best keeps Channel 16 available for its intended purpose?

  1. Holding long conversations on Channel 16 to avoid changing channels
  2. Making initial contact on Channel 16 and then moving to a working channel Correct answer.
  3. Broadcasting music on Channel 16 to test the transmitter
  4. Using Channel 16 for routine position reports between vessels

Explanation

Channel 16 is reserved for distress, urgency, safety and calling, so routine exchanges should begin there and move promptly to a working channel such as 06. This keeps the calling channel clear for emergency traffic.

Question 16Marine VHF radio operating procedures and distress, urgency and safety communications

A vessel wishes to send a Mayday relay for a casualty whose distress call was faint. How should the relay be introduced?

  1. Securite, this is the relaying vessel, followed by the casualty's details
  2. Mayday Relay, spoken three times, followed by this is and the relaying station's identification, then the casualty's details Correct answer.
  3. Pan Pan, this is the relaying vessel, followed by the casualty's details
  4. Mayday, this is the relaying vessel, followed directly by the casualty's details

Explanation

A Mayday relay opens with Mayday Relay repeated three times, then this is and the relaying station's name and callsign, followed by the details of the vessel in distress. The word Relay distinguishes the transmitting station from the casualty.

Question 17Marine VHF radio operating procedures and distress, urgency and safety communications

What information should a vessel give when requesting a radio check from a coast station?

  1. Its position, the channel in use and a request for a signal report Correct answer.
  2. The names of all crew on board
  3. A full Mayday message
  4. Only the word test repeated three times

Explanation

A radio check should state the vessel's identification, position and the channel being used, and ask for a signal report so the coast station can confirm readability. This lets the operator verify the installation without occupying emergency channels unnecessarily.

Question 18Marine VHF radio operating procedures and distress, urgency and safety communications

A vessel hears a Pan Pan message from another vessel reporting engine failure and drifting towards a rocky shore. How should the listening vessel respond if it can assist?

  1. Acknowledge on Channel 16 and offer assistance, then move to a working channel to coordinate Correct answer.
  2. Transmit a Mayday relay immediately
  3. Switch to Channel 70 and send a DSC alert
  4. Remain silent because only coast stations may answer urgency traffic

Explanation

Any station able to assist should acknowledge the urgency message and offer help, then shift to a working channel to coordinate without blocking Channel 16. Coast stations coordinate the overall response, but nearby vessels are often best placed to give immediate help.

Question 19Marine VHF radio operating procedures and distress, urgency and safety communications

Why should a vessel avoid transmitting on Channel 16 during a distress incident unless it is directly involved?

  1. Channel 16 is automatically disabled during distress traffic
  2. Unnecessary transmissions can interfere with the distress traffic and the controlling station's coordination Correct answer.
  3. Only DSC may be used once a distress is declared
  4. Channel 16 changes frequency during an incident

Explanation

During distress traffic, Channel 16 must be kept clear so the casualty and the controlling station can exchange critical information without interference. Stations not involved should listen and stand by, transmitting only if they can assist or are directed to.

Question 20Marine VHF radio operating procedures and distress, urgency and safety communications

A vessel's VHF radio fails completely while it is offshore and in no immediate danger. Which action is most appropriate?

  1. Transmit a Mayday on a hand-held set to attract attention
  2. Rely on visual and other means of signalling and report the failure at the next opportunity Correct answer.
  3. Continue the voyage without informing anyone
  4. Broadcast a Securite message on Channel 06 about the radio failure

Explanation

With no working radio, the vessel should use alternative means such as visual signals and report the equipment failure when possible, so that authorities are aware of the reduced capability. Falsely declaring distress would be improper and could divert resources.

Question 21Marine VHF radio operating procedures and distress, urgency and safety communications

Which statement correctly distinguishes the distress call from the distress message?

  1. The message is sent on Channel 70, while the call is sent on Channel 16
  2. The call contains the position, while the message contains only the vessel name
  3. The call and message are identical and transmitted once
  4. The call identifies the station and signals distress, while the message contains position, nature of distress and assistance required Correct answer.

Explanation

The distress call is the short alert (Mayday three times, this is, identification) that grabs attention, while the distress message supplies the details rescuers need: position, nature of distress, assistance required and persons on board. Both are transmitted by voice on Channel 16.

Question 22Marine VHF radio operating procedures and distress, urgency and safety communications

A vessel in distress gives its position as an estimate based on dead reckoning with no GPS fix. How should this be handled in the distress message?

  1. Wait until an exact GPS fix is obtained before transmitting
  2. Give a false precise latitude and longitude to appear accurate
  3. State the position and make clear that it is an estimate or DR position Correct answer.
  4. Omit the position entirely to avoid misleading rescuers

Explanation

Rescuers need the best position available, and stating that it is a dead reckoning estimate tells them how much uncertainty to allow. Delaying the distress message to obtain a precise fix wastes critical time.

Question 23Marine VHF radio operating procedures and distress, urgency and safety communications

During a distress incident, a station that is not involved hears the controlling coast station issue Silence Mayday. What must the station do?

  1. Transmit a Mayday relay to confirm it heard the silence order
  2. Change to Channel 70 and acknowledge the distress
  3. Continue its routine traffic on Channel 16 as normal
  4. Cease transmitting on the affected channel and maintain a listening watch until Silence Fini is heard Correct answer.

Explanation

Silence Mayday imposes radio silence on all stations except those handling the distress, so an uninvolved station must stop transmitting on that channel and keep listening. Normal working may resume only when Silence Fini is transmitted.

Question 24Marine VHF radio operating procedures and distress, urgency and safety communications

A vessel transmits a DSC distress alert and then realises the situation has been resolved and no assistance is needed. What is the correct course of action?

  1. Send a Securite message on Channel 06 and take no further action
  2. Ignore the alert and carry on, since no voice message was sent
  3. Transmit a DSC or voice cancellation on Channel 16 stating that the distress alert was inadvertent and is cancelled Correct answer.
  4. Switch off the radio to prevent further transmissions

Explanation

An inadvertent distress alert must be cancelled promptly so that rescue services are not launched unnecessarily, using a voice or DSC cancellation on the appropriate channel. Leaving the alert uncancelled wastes search and rescue resources and may trigger a full response.

Question 25Marine VHF radio operating procedures and distress, urgency and safety communications

A vessel's operator hears a Mayday from a station that gives only a partial message before transmission stops. What is the most appropriate action?

  1. Wait silently for at least one hour before responding
  2. Broadcast a Securite warning to other vessels and take no other action
  3. Assume the distress is resolved and resume normal working
  4. Acknowledge the Mayday, attempt to establish contact, and relay the details to a coast station Correct answer.

Explanation

When a distress message is incomplete, a station that heard it should acknowledge, try to re-establish contact with the casualty, and pass the details to a coast station so a response can be coordinated. Silence or delay risks the casualty's safety.

Question 26Marine VHF radio operating procedures and distress, urgency and safety communications

On a New Zealand marine VHF set, which channel is designated as the distress, safety and calling channel?

  1. Channel 62
  2. Channel 6
  3. Channel 16 Correct answer.
  4. Channel 13

Explanation

Channel 16 (156.800 MHz) is the international VHF distress, safety and calling frequency, and in New Zealand it is monitored for distress, urgency and safety traffic. Routine calling is initiated there but working traffic must move to a ship-to-ship channel. Channel 6 is used for intership safety traffic, not distress calling.

Question 27Marine VHF radio operating procedures and distress, urgency and safety communications

What is the correct spoken form of the distress signal when a vessel transmits a Mayday call on VHF?

  1. Mayday spoken once
  2. Pan Pan spoken three times
  3. Mayday spoken three times
  4. Mayday spoken twice Correct answer.

Explanation

The distress call consists of the word Mayday spoken three times, followed by This is and the vessel's identity, repeated as needed. The standard format requires the distress signal itself to be transmitted three times in the call, while the vessel's name or callsign is also repeated. Using the correct repetition pattern lets stations recognise the call immediately as genuine distress traffic.

Question 28Marine VHF radio operating procedures and distress, urgency and safety communications

Which transmission priority order applies when a VHF channel is carrying several types of traffic at once?

  1. Routine, safety, urgency, distress
  2. Distress, safety, urgency, routine
  3. Safety, distress, routine, urgency
  4. Distress, urgency, safety, routine Correct answer.

Explanation

Radio traffic is ranked distress first, then urgency, then safety, then routine. Any station must stop transmitting when higher-priority traffic is heard on the channel. This hierarchy is what allows a Mayday to interrupt an ordinary working exchange.

Question 29Marine VHF radio operating procedures and distress, urgency and safety communications

A vessel is in grave and imminent danger and requires immediate assistance. Which radiotelephone signal should be transmitted on VHF?

  1. Pan Pan spoken three times
  2. Securite spoken three times
  3. A DSC routine call to a coast station
  4. Mayday spoken three times Correct answer.

Explanation

Mayday is reserved for grave and imminent danger where immediate assistance is required, such as a vessel sinking or a person overboard at night. Pan Pan covers urgent but less critical situations, and Securite is for safety information. Routine DSC calls carry no priority and will not alert stations as distress traffic.

Question 30Marine VHF radio operating procedures and distress, urgency and safety communications

What does the spoken phrase This is mean when used in a VHF distress or urgency transmission?

  1. It requests a reply from all stations
  2. It marks the end of the transmission
  3. It identifies the station transmitting the message Correct answer.
  4. It orders other stations to keep silent

Explanation

In radiotelephony, This is introduces the identity of the transmitting station, usually the vessel name or callsign spoken once or twice. It is a standard separator between the signal or addressee and the station's own identity. It does not end a transmission, request replies or impose silence.

Question 31Marine VHF radio operating procedures and distress, urgency and safety communications

Which channel is designated in New Zealand for routine ship-to-ship communications after contact is established on Channel 16?

  1. Channel 6 Correct answer.
  2. Channel 70
  3. Channel 62
  4. Channel 16

Explanation

Channel 6 is widely used for intership working traffic, allowing vessels to move off the calling channel once contact is made. Channel 70 is reserved for DSC and must never be used for voice, and Channel 16 is kept for calling and distress. Working on Channel 6 leaves the distress channel clear.

Question 32Marine VHF radio operating procedures and distress, urgency and safety communications

How should the word Over be used at the end of a VHF transmission?

  1. To identify the vessel transmitting
  2. To indicate a reply is expected from the station addressed Correct answer.
  3. To impose radio silence on the channel
  4. To indicate the transmission is finished and no reply is expected

Explanation

Over invites the other station to reply and marks the end of your turn in the exchange. It keeps the conversation orderly, particularly on a shared channel where several stations may be listening. Out is used instead when no reply is expected.

Question 33Marine VHF radio operating procedures and distress, urgency and safety communications

Which statement about the content of a distress message is correct?

  1. It should give position, nature of distress, assistance required and persons on board Correct answer.
  2. It should be transmitted on Channel 70 in voice
  3. It should be limited to the vessel name and position only
  4. It should be sent only after permission from another vessel

Explanation

A distress message should contain the vessel's identity, position, nature of distress, assistance required and number of persons on board, plus any other useful information such as weather or drift. These details allow rescuers to plan the response. Omitting persons on board or the nature of the problem slows the rescue.

Question 34Marine VHF radio operating procedures and distress, urgency and safety communications

A vessel's engine has failed and it is drifting in calm water, in no immediate danger, and it needs a tow arranged. Which signal should be used on VHF?

  1. Securite
  2. Pan Pan Correct answer.
  3. No special signal; a routine call is sufficient
  4. Mayday

Explanation

Pan Pan is the urgency signal for a serious situation that threatens safety but does not yet involve grave and imminent danger. A drifting vessel with no immediate hazard and time to arrange a tow fits that category. Mayday would be premature while no immediate danger exists.

Question 35Marine VHF radio operating procedures and distress, urgency and safety communications

Which information should be included when a vessel transmits a Mayday call on VHF?

  1. Vessel name, the name of the skipper and the vessel's home port
  2. Vessel name, the intended destination and estimated time of arrival
  3. Vessel name, the number of crew and the vessel's registration number only
  4. Vessel name repeated three times, position, nature of distress and assistance required Correct answer.

Explanation

The distress call should identify the vessel (repeated), give its position, state the nature of distress and the assistance required, and include persons on board. These are the facts a rescue coordinator needs to act. Personal details or voyage plans do not help the immediate rescue.

Question 36Marine VHF radio operating procedures and distress, urgency and safety communications

A vessel hears a Mayday from a nearby yacht but the yacht's position is unclear. What is the most appropriate action for the listening vessel?

  1. Wait in silence and take no action until a coast station responds
  2. Acknowledge the Mayday and offer assistance if able, while allowing the coast station to coordinate Correct answer.
  3. Switch off the radio to avoid interfering with the distress traffic
  4. Immediately transmit its own Mayday to take over the incident

Explanation

A station hearing a distress call should acknowledge it if no coast station has done so, and offer assistance if it is able. It should not transmit its own Mayday, which would confuse the incident. Once a coast station or rescue coordination centre takes control, other stations follow its instructions.

Question 37Marine VHF radio operating procedures and distress, urgency and safety communications

When a vessel makes a routine call to a coast station on Channel 16, what should happen once the coast station answers?

  1. The vessel should switch to Channel 70 for voice
  2. The vessel should continue the conversation on Channel 16
  3. The vessel should end the call without giving further details
  4. The vessel should move to a working channel nominated by the coast station Correct answer.

Explanation

Channel 16 is a calling channel, so once contact is established the stations move to a working channel, usually one nominated by the coast station. This keeps the calling and distress channel available. Continuing a routine conversation on Channel 16 blocks distress traffic.

Question 38Marine VHF radio operating procedures and distress, urgency and safety communications

A vessel's VHF radio is receiving but its transmissions are not being heard by other stations. Which action is most appropriate?

  1. Check the antenna, connections and power, and request a radio check on a working channel Correct answer.
  2. Switch to Channel 70 and try voice there
  3. Transmit a Mayday to test whether anyone can hear
  4. Assume the radio is working and continue normal operations

Explanation

If transmissions are not being received, the likely causes are antenna, cabling, power or microphone faults. Checking these and requesting a radio check on a working channel confirms whether the set is transmitting. A Mayday must never be used as a test, and Channel 70 is for DSC only.

Question 39Marine VHF radio operating procedures and distress, urgency and safety communications

What is the correct way to request a radio check from a coast station on VHF?

  1. Call the coast station, give your vessel name and position, and ask for a radio check Correct answer.
  2. Transmit Mayday and ask for signal strength
  3. Call any vessel on Channel 16 and ask if they can hear you
  4. Transmit Securite and ask for a radio check

Explanation

A radio check is a routine request: call the station, identify your vessel and position, and ask for a radio check. The coast station replies with signal strength and readability. Mayday and Securite are reserved for distress and safety traffic and must not be used for testing.

Question 40Marine VHF radio operating procedures and distress, urgency and safety communications

A vessel is asked to keep a listening watch on Channel 16 while underway. Which practice best supports this requirement?

  1. Switching to Channel 6 and monitoring only that channel
  2. Keeping the volume low and the squelch set so weak signals are not missed Correct answer.
  3. Leaving the squelch fully open so all noise is heard
  4. Turning the radio off when not transmitting

Explanation

A listening watch depends on the receiver being on, the volume audible and the squelch set so that weak distress signals are not blocked. Leaving the squelch fully open produces constant noise that masks calls. Working channels may be used, but Channel 16 must remain monitored, often with dual watch.

Question 41Marine VHF radio operating procedures and distress, urgency and safety communications

A vessel receives a DSC distress alert on Channel 70. What should it do next?

  1. Ignore the alert unless it knows the vessel
  2. Acknowledge on Channel 70 by voice
  3. Switch to Channel 16 and listen for the distress call and message Correct answer.
  4. Transmit a Mayday relay immediately

Explanation

A DSC distress alert is a digital alert; the voice distress call and message follow on Channel 16. Stations should switch to Channel 16, listen, and acknowledge or assist as appropriate. Voice acknowledgement is not made on Channel 70, which is reserved for DSC.

Question 42Marine VHF radio operating procedures and distress, urgency and safety communications

Which statement correctly describes the purpose of the urgency signal Pan Pan?

  1. To indicate a serious situation that may develop into distress but does not yet require immediate assistance Correct answer.
  2. To indicate a station is in grave and imminent danger
  3. To request a radio check from a coast station
  4. To announce a message concerning the safety of navigation

Explanation

Pan Pan signals urgency: a serious situation concerning the safety of a vessel or person that has not yet become grave and imminent danger. It gives the message priority over routine and safety traffic. Mayday is used once immediate danger exists, and Securite covers safety information.

Question 43Marine VHF radio operating procedures and distress, urgency and safety communications

What is the correct procedure word to end a VHF exchange when no reply is expected?

  1. Over
  2. Roger
  3. Wilco
  4. Out Correct answer.

Explanation

Out closes a transmission and indicates that no reply is expected. Over invites a reply, while Roger and Wilco are acknowledgements of receipt and compliance. Using Out correctly prevents unnecessary replies and keeps the channel clear.

Question 44Marine VHF radio operating procedures and distress, urgency and safety communications

A vessel hears a faint Mayday call and decides to relay it. How should the relay be introduced?

  1. Mayday spoken three times, followed by the distressed vessel's name
  2. Mayday Relay spoken three times, followed by This is and the relaying vessel's identity Correct answer.
  3. Pan Pan spoken three times, followed by the relaying vessel's identity
  4. Securite spoken three times, followed by the distressed vessel's position

Explanation

A relay is introduced with Mayday Relay repeated three times, then This is and the relaying station's identity, so listeners know the distress belongs to another vessel. The relaying vessel then passes on the information it heard. It must not pretend to be the casualty by using a plain Mayday call.

Question 45Marine VHF radio operating procedures and distress, urgency and safety communications

A vessel in distress gives its position as an estimate based on dead reckoning, with no GPS fix available. How should this be handled?

  1. Give the last known GPS position without qualification
  2. Refuse to give a position until a GPS fix is obtained
  3. Give the estimated position and state clearly that it is an estimate Correct answer.
  4. Give the position of the nearest coast station instead

Explanation

An estimated position is far more useful than none, provided it is clearly described as an estimate based on dead reckoning. Rescuers can then plan a search pattern around it. Withholding a position or giving a false precise fix misleads the rescue effort.

Question 46Marine VHF radio operating procedures and distress, urgency and safety communications

During a distress incident, what does the phrase Silence Mayday mean?

  1. Routine traffic may resume on Channel 16
  2. The distressed vessel must stop transmitting
  3. The coast station is closing the incident
  4. All stations must stop transmitting until the distress traffic is complete Correct answer.

Explanation

Silence Mayday, usually imposed by the station controlling the distress traffic, orders all stations to cease transmitting so the incident can be handled without interference. Only the controlling station, or stations directly involved, transmit until Silence Fini is given. It does not silence the casualty.

Question 47Marine VHF radio operating procedures and distress, urgency and safety communications

A vessel transmits a DSC distress alert and then finds the situation has been resolved and no assistance is needed. What should it do?

  1. Transmit a Securite message announcing the cancellation
  2. Switch the radio off and continue the voyage
  3. Transmit a DSC distress cancellation and a voice cancellation on Channel 16 Correct answer.
  4. Do nothing; the alert will expire automatically

Explanation

A false or resolved distress alert must be cancelled promptly by DSC and by voice on Channel 16 so that stations and rescue authorities stand down. The cancellation identifies the vessel and states that assistance is no longer required. Leaving the alert uncancelled triggers an unnecessary search.

Question 48Marine VHF radio operating procedures and distress, urgency and safety communications

A vessel's operator hears a Mayday that stops partway through, before any position is given. What is the most appropriate immediate action?

  1. Wait for the vessel to call again before doing anything
  2. Transmit a Mayday relay immediately with an estimated position
  3. Acknowledge the partial Mayday, attempt to obtain the missing details, and alert the coast station Correct answer.
  4. Assume the vessel has recovered and take no action

Explanation

A partial distress call may mean the transmission was cut short by the emergency itself, so it should be treated as genuine. The listening station should acknowledge, try to obtain the missing details and inform the coast station. Assuming recovery or waiting silently risks losing the chance to help.

Question 49Marine VHF radio operating procedures and distress, urgency and safety communications

A vessel is taking on water after striking a submerged object and is in immediate danger of sinking. Which signal and priority is correct?

  1. Pan Pan, because the vessel is still afloat
  2. Mayday, because there is grave and imminent danger Correct answer.
  3. A routine call to the nearest marina
  4. Securite, because the hazard is navigational

Explanation

A vessel in immediate danger of sinking is in grave and imminent danger, so Mayday is the correct signal. The fact that the vessel is still afloat does not downgrade the situation; the test is whether immediate assistance is required. Pan Pan would be appropriate only if the danger were not yet imminent.

Question 50Marine VHF radio operating procedures and distress, urgency and safety communications

A vessel hears another station impose Silence Mayday during a distress incident. What is the correct conduct for a vessel not involved in the incident?

  1. Continue routine transmissions on Channel 16 as normal
  2. Switch to Channel 70 and continue voice communications
  3. Cease transmitting on the channel and maintain a listening watch until Silence Fini Correct answer.
  4. Transmit a Mayday relay to confirm the silence order

Explanation

Silence Mayday requires all stations to stop transmitting so the distress traffic can proceed without interference. Uninvolved vessels keep a listening watch and resume only when Silence Fini is given. Continuing routine traffic or relaying unnecessarily undermines the controlling station's management of the incident.