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6. Distress, urgency and safety communications
Safety of navigation is a major concern for all ships, from huge tankers to small pleasure boats, even if the vessels are not participating in the Global Maritime Distress and Safety System (GMDSS). The latest issue of the ITU’s Radio Regulations make distress, urgency and safety voice procedures compatible for all vessels, whether equipped with VHF–DSC radios or with voice-only radios without any DSC functions. A marine VHF radio with integrated DSC functions allows transmission of a distress alert by the push of a DISTRESS button, and this alert will be received by all ships and coast stations within range of their VHF–DSC by means of its automatic watch receiver. The most vital information, namely the identity and position of the vessel in distress and (generally) the nature of distress, are made available immediately. A distress alert, and also a distress relay, must be followed by the appropriate voice MAYDAY calls on channel 16, so as to inform stations without DSC facilities. Similarly, an urgency announcement and a safety announcement sent by DSC are followed respectively by a PAN PAN and by a SECURITE voice message, with all necessary details supplied. These operating procedures for receiving or transmitting a distress, urgency or safety communication by marine VHF radio are strictly regulated and should be well understood by radio operators. Since it is not possible to practise distress, urgency and safety procedures on a real radio, a VHF radio simulator is the ideal method to ensure you are ready for the unexpected.
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General provisions The Global Maritime Distress and Safety System (GMDSS) has been set up to provide an international communication network to assist vessels in distress. All distress communications in the maritime mobile service – whether by radiotelephony, Digital Selective Calling (DSC), satellite techniques and/or direct-printing telegraphy (telex) – must be conducted strictly in accordance with correct procedures. This ensures that vessels in distress obtain help without delay. There are 3 levels of emergency defined in the GMDSS and, in order of priority, they are: Distress, Urgency and Safety – well known by their signals of MAYDAY, PAN PAN and SECURITE used in radiotelephony. Digital Selective Calling (DSC) does not replace traditional radiotelephony but uses the latest technology to enhance it. A brief digital sequence will activate all alarms in any VHF–DSC radios within range and alert any operators of those radios to listen on the distress, urgency and safety channel for the subsequent voice call and message. A digital selective call transmitted on channel 70 contains the identity of the calling station and the priority or purpose of the call. Most importantly, a distress alert also includes the position of the distressed vessel and possibly the nature of the distress. But there are many traditional fixed-mount VHF radios and handheld VHF sets in use without the DSC facility. Therefore each and every DSC call should be immediately followed by a radiotelephony call and message so that voice-only stations are not excluded from modern marine communications. The revised procedures of the latest ITU Radio Regulations make this possible.
Terminology of calls and messages We use the generic term call in the broadest sense to designate both DSC calls and radiotelephony (ie voice) calls – using the term alert to designate all types of DSC call is incorrect. The Radio Regulations terminology of DSC calls is: distress alert, urgency announcement, safety announcement and routine call. Category
Priority
DSC calls
Distress
1
Distress alert
Urgency
2
Safety
3
Routine
4
Signals in radiotelephony distress signal: MAYDAY
Urgency announcement Safety announcement
urgency signal:
Routine call
—
PAN PAN
safety signal: SECURITE
Kind of message Distress call and message Urgency call and message Safety call and message routine message (none of the above)
Priority of communications VHF radio calls have four levels of priority defined for maritime mobile services: 1. Distress alerts, distress acknowledgements, distress relays, distress traffic. 2. Urgency announcements, urgency calls and messages. 3. Safety announcements, safety calls and messages, test calls, position requests. 4. Routine: individual routine calls, group calls, polling and telephone call requests.
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Distress communications Distress is defined as a situation where, in the opinion of the master, a vessel, aircraft, vehicle or person is in grave and imminent danger and requires immediate assistance. A dismasting or a disabled engine offshore does not in itself qualify for a distress call. However, a yacht sinking, or a man overboard in severe weather or sea conditions and with little chance of recovery by those on board, is in grave and imminent danger and would qualify for a distress communication. A distress communication by a VHF–DSC comprises a distress alert that is started with the DISTRESS button and sent by DSC, and then a voice distress call and a distress message with MAYDAY on channel 16, providing the position and requesting immediate assistance. The form of distress communications is defined by the RR Article 32. Never use the Distress call when your ship or person is not in an emergency situation. A distress call should be transmitted only when immediate help is needed. Only the skipper of a vessel can authorise the sending of a distress alert. It has priority over all other radio traffic and automatically imposes radio silence on all stations in the area not involved in the rescue.
Distress alert by DSC The red DISTRESS button makes it possible to transmit a distress alert automatically with the MMSI number of the boat, the position and the UTC time at this position, and possibly the nature of the distress. The DISTRESS button is covered by a red flip-top cover. This spring-loaded cover must be lifted before the button can be pressed, so as to avoid accidental depression. Lift the cover on the DISTRESS button and press the button briefly. The Distress alert menu will appear on the DSC screen. If you press and hold down the DISTRESS button for 5 seconds, a Distress alert will be sent immediately with the default option for the nature of distress as Undesignated. As the distress alert includes the ship’s position and the UTC time when it was valid, check the GPS position information. If no valid position is indicated, the latitude and longitude values flash and the Posn function appears, which allows updating the position manually. See chapter 5 on how to update your position manually. If you have sufficient time, select the appropriate nature of the distress, presented as a number of options. Scroll through via the Sel soft key – ie Fire, Explosion; Flooding; Collision; etc. Then press
to confirm.
Lift the cover on the DISTRESS button, press and hold down for 5 seconds using the DSC countdown to zero (see below). If the DISTRESS button is released before five seconds are up, the radio will return to normal operation and no distress alert will be sent.
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The DSC controller will count down 5 4 3 2 1 (0). During this 5-second period, the VHF radio will emit a loud warning beep every second.
Channel 70 is automatically selected and the distress alert will be transmitted in 3.5 seconds (all details are included in the sequence, sent 5 times to allow automatic error correction). After transmitting the distress alert, the dedicated watch receiver waits for an acknowledgement on channel 70. After the transmission of the distress alert, the transceiver is set to channel 16 automatically. The distress alert is automatically retransmitted approximately every 3.5 to 4.5 minutes (at random intervals) until an acknowledgement is received or this repetition is stopped by switching the VHF unit off and then on again. When the stations within range receive the distress alert, their VHF–DSC devices sound an audible distress alarm and details of the distress are displayed. Each receiver tunes automatically to channel 16 for voice reception. The distress alert sequence contains the MMSI number of the vessel in distress, its position together with the time of this position, and the nature of the distress. It is recommended to wait 15 seconds before transmitting your voice distress call and message on channel 16. The 15 seconds of time allows the reception of an acknowledgement on channel 70. If the ship in distress is in sea area A1, an MRCC with permanent watch-keeping will acknowledge recept of the alert immediately. Outside sea area A1, or in poor transmission conditions, a SOLAS vessel could also send an acknowledgement by DSC. As the VHF radios on board small craft have a single antenna, reception of DSC on channel 70 is suspended during any voice transmission. After 15 seconds, even if no acknowledgement has been received, you must continue with a distress call and message by voice on channel 16.
This will be received even by vessels without DSC and could contain additional information useful to the search-and-rescue operations.
Distress call and message (voice) The signal that every yacht skipper hopes never to make is the distress signal, MAYDAY. The word MAYDAY is the distress signal in voice radio communications, deriving from the French venez m'aider, or m'aidez, meaning come and help me. English may be the international language of radio, but the procedural words are French.
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The procedure for a distress call and message is practically the same for all marine radios, including traditional and handheld VHF devices without DSC functions, and marine MF/HF radios. Press the key for direct access to channel 16 and set high power (although on most VHF-DSC units this is done automatically). Adjust the squelch threshold level.
Distress call A distress call has the following form: the distress signal MAYDAY spoken three times; the words This is; the name of the vessel in distress, spoken three times; the call sign or other identification of the vessel in distress, spelled; and the MMSI number of the vessel in distress (if the initial alert has been sent by DSC). Press and hold down the PTT transmit button of the microphone, and say slowly and clearly (in English or in the language understood in the region): MAYDAY, MAYDAY, MAYDAY.
THIS IS {name of the vessel}, {name of the vessel}, {name of the vessel}, CALL SIGN {call sign of the vessel}, MMSI {MMSI of the vessel}. The mayday call does not have to be addressed to a particular station because the word MAYDAY itself is the distress signal used to alert all stations, without saying ALL STATIONS. The call sign and the MMSI number provide positive identification of your vessel; more than one ship may share the same name, but your call sign and MMSI is unique. If the boat has no MMSI number and the distress call is transmitted by voice only, the MMSI will be omitted.
Distress message The distress message follows the distress call without a break, ie without releasing the PTT transmit button on the microphone. Remember that other people will be trying to write down your position and other details of the distress. The Distress message has the following form: the distress signal MAYDAY spoken only once; (here, the words This is are not included); the name of the vessel in distress; the call sign or other identification; and the MMSI (if the initial alert has been sent by DSC). Then the vessel’s position should be given – as the latitude and longitude or, if they are not known or if time is inadequate, as relative to a known or charted geographical location. MAYDAY.
{name of the vessel}, CALL SIGN {call sign of the vessel}, MMSI {MMSI of the vessel}. POSITION {vessel’s position}. {Nature of the distress}. I REQUIRE IMMEDIATE ASSISTANCE. {Number of people on board}. {Any other information, which might facilitate rescue.} OVER. Then the need for immediate assistance and other useful information should be given. You must describe the nature of your distress: fire, collision, sinking; the kind of assistance required; any other useful information, such as the number of crew on board, the type of boat, and whether you have a life raft, flares, handheld VHF or EPIRB.
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The Distress message ends with Over, an invitation to reply. Remember to release the PTT switch. Even if stations with VHF–DSC radio receive the position on their display screen, it is essential to repeat the position in the voice message so that ships equipped with traditional VHF without DSC can be informed. You can expect an immediate acknowledgement, either from another ship in the area or most likely from a coast station or rescue co-ordination centre (RCC). If this is not forthcoming, check your equipment, make sure you have switched to 25 watts of power and repeat your distress message.
The nature of the distress in the GMDSS In the GMDSS, a list of current categories of distress is established and available in the menu of a DSC controller for ease of transmission. These are as follows: Undesignated
Undesignated distress
Fire
Fire, explosion
Flooding
Flooding
Collision
Collision
Grounding
Grounding
Listing Sinking Disabled, adrift Abandoning Piracy
Listing (inclination of the vessel to one side); in danger of capsizing Sinking A vessel damaged or impaired in such a manner as to be incapable of proceeding on its voyage Evacuation of crew and passengers from vessel following a distress Piracy; armed robbery attack
Man overboard Man overboard Undesignated distress alert If you do not have time to select the nature of your distress when making a distress alert, the sequence includes the default value Undesignated. This is known as an Undesignated (undefined, quick or simple) distress alert. Designated distress alert If you have time to select the nature of the distress category (by means of the distresssetting option of the menu), the nature of your distress will be included in the sequence and you will have issued a Designated (regular) distress alert. It is strongly recommended that an emergency procedure card is displayed in full view next to the VHF radio, so any crew member can know how to transmit a distress alert immediately followed immediately by a distress call and message. The template of the VHF radio distress procedure to be used in grave and imminent danger when immediate assistance is required is provided on the inside cover page. Make such an emergency procedure card with the name, call sign and the MMSI number of your boat.
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Ship in distress – example Example: you are on board the Swedish yacht Estelle crossing the Chanel Islands and heading to southern England. Following an explosion, the ship is sinking. In this distress situation you need immediate assistance. Having practised distress procedures on a simulator, you react promptly by transmitting a distress alert, followed by a MAYDAY call. Press the red DISTRESS button once and release, to access the Distress Alert screen on your radio. Check the positional data and select the nature of the distress.
Verify the position of Estelle and the time in UTC when it was valid. Correct data is available from the GPS. With the Sel soft key, quickly select Sinking. Press and hold down the DISTRESS button for 5 seconds, the Distress alert will be transmitted. The MMSI number of Estelle, the distress position, and the fact that the ship is sinking are transmitted to all stations within range and using VHF–DSC radio. The following calling sequence is transmitted by DSC:
As in many coastal areas, the Channel Islands are in sea area A1 of the GMDSS, where at least one MRCC is keeping watch; here the French CROSS Jobourg is operational. The VHF of Estelle is switched automatically to channel 16 and to high power of 25 watts. Vessels and coast radio stations within 20 nautical miles or so will have all received the distress alert of Estelle. In less than 10 seconds, an acknowledgement from CROSS Jobourg is received. This acknowledgement is received not only by Estelle, but all the other stations in the vicinity. The distress communication has absolute priority over any other communications. If channel 16 is already in use, your broadcast takes precedence. The distress call and message have a well defined sequence as given above, and it is very important to give your message in the right order. Your distress call would be:
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MAYDAY, MAYDAY, MAYDAY.
This is Swedish yacht Estelle, Estelle, Estelle, call sign Sierra Foxtrot Charlie Five Four Zero Three. MMSI number 2 6 5 5 0 0 2 6 0. Listeners to the transmission must cease any traffic and should be ready to write down the details. Your distress message is pronounced slowly and clearly to be understood, as follows: MAYDAY.
Estelle, call sign Sierra Foxtrot Charlie Five Four Zero Three. MMSI number 2 6 5 5 0 0 2 6 0. Position West of Roche Douvres, 7 nautical miles. 4 9 degrees 0 6 decimal 0 0 minutes North, 0 0 2 degrees 5 9 decimal 4 0 minutes West, time 1 3 2 0 UTC. We had an explosion, the ship is sinking. We need immediate assistance. Six persons on board. 39 feet sailing boat, white freeboard. We are leaving the ship. The life-raft will remain tied to the ship until it sinks. Handheld VHF on channel 16. EPIRB and SART are activated. Over.
Stages of distress communications While there are no two identical distress situations, the typical sequence of distress communications is as follows:
The ship in distress broadcasts a distress alert by DSC on channel 70 to all ships in the area, as well as to coast radio stations including any shore-based MRCCs. The MRCC in charge will immediately transmit an acknowledgement by DSC.
This acknowledgement of the MRCC is addressed to all stations.
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The ship in distress transmits a distress call and a message by voice on channel 16, repeating all data and possibly giving more details.
All other ships with voice-only VHF radios listening on channel 16 are thereby also informed about the distress. Radio silence is imposed on VHF channel 16, so only essential distress traffic is allowed. The coast radio station controlling the search-and-rescue operations (an MRCC) transmits a voice acknowledgement call using the procedural words RECEIVED MAYDAY.
Other ships in the vicinity might also acknowledge the reception of the distress call by voice on channel 16, but only if they can offer assistance. Now suppose that a rescue vessel or helicopter is approaching the ship in distress:
The distress traffic between the MRCC, the ship in distress and the rescue vessel will occur on channel 16. Each message starts with the distress signal MAYDAY, followed by the name of the vessel in distress. For quick reference, such a VHF Radio Distress procedures card is shown on the inside cover of this handbook. It can be used both for vessels fitted with DSC and for vessels only equipped with a VHF radio without DSC.
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Receiving a distress alert – example When a VHF–DSC radio receives a distress alert, it will sound an audible distress alarm and the following information will appear: The MMSI number of the ship in distress and channel 16 is imposed for subsequent voice communications. Stop the alarm by OK. Select More to see details of the distress. In addition to the MMSI number of the ship in distress, the extra details supplied are the nature of distress, the ship’s position expressed as latitude and longitude and the UTC time of this position. Listen and note the message transmitted on channel 16. For example: MAYDAY, MAYDAY, MAYDAY.
This is yacht Silver Crest, Silver Crest, Silver Crest, call sign Papa Charlie Three Three Four Nine. MMSI number 2 4 4 2 6 0 2 4 6. The transmission of Silver Crest is suddenly interrupted, the vessel is flooding …
What to do if you receive a distress call In the GMDSS, normally an MRCC will initiate and coordinate search-and-rescue operations. Sometimes, large vessels with considerable facilities are involved. Nevertheless, you as master of a small craft have the obligation to accept distress communications with absolute priority, and possibly answer if so needed. You should attract attention, make known the condition and location of the station in distress, and obtain or provide assistance. Allow a few minutes for the MRCC to acknowledge a distress alert by DSC, which prevents automatic repetitions of the alert by the vessel in distress. The MRCC will have the responsibility and competence to coordinate the search-and-rescue operations. A small ship’s VHF–DSC radio with Class D controller cannot send a distress alert acknowledgement by DSC. Even if you happen to have a Class A controller (which has a distress alert acknowledgement DSC function), never acknowledge a distress alert by DSC. The acknowledgement can, however, be made by you by radiotelephony on channel 16, as RECEIVED MAYDAY. If you cannot offer assistance, keep off the radio. However, if you hear no acknowledgement or distress traffic on channel 16, inform the MRCC by relaying the distress situation by any means – most appropriately by a distress relay call to an individual station (never to all stations), followed by a MAYDAY RELAY on channel 16. While there are no two identical distress situations at sea, the general procedure for what to do if you receive a distress alert on your VHF radio can be summarised in a flowchart (see below). Similar logic can be applied in a case of receiving distress calls and messages by voice or when you observe sound and/or visual distress signals (eg red flares fired, N&C flags, an orange smoke signal) from a nearby boat.
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Distress relay calls A ship station which learns that a vessel is in distress (for example, by a radio call or by observation) must initiate and transmit a distress relay call on behalf of the vessel in distress once it has ascertained that any of the following circumstances apply: • on receiving a distress alert or distress call that is not acknowledged by a coast station or another vessel within five minutes; or • on learning that the vessel in distress is otherwise unable or incapable of participating in distress communications, if the master of the ship not in distress considers that further help is necessary. The station transmitting a distress relay call should make it clear that it is not in distress itself. The distress relay should contain the identification of the vessel in distress, its position and all other information that might facilitate rescue. Coast stations and large SOLAS ships equipped with VHF–DSC with a class A controller have a Distress Relay function to all ships or to an individual station. Small craft using a class D controller could send a distress relay call on behalf of another ship only to an individually addressed station (normally an MRCC).
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Distress relay call sent by DSC Continuing the previous example, relaying the distress of Silver Crest to a rescue coordination centre on shore: The distress relay call can only be addressed to a particular coast radio station (never to all stations). The MMSI of the ship in distress, her position and the nature of the distress should be transmitted, as far as these details are known. The MMSI of the ship in distress, the longitude and latitude and UTC time of its position, together with the nature of the distress, are all typed in based on written notes from the original distress message (never taken directly from a received distress alert). If the Distress Relay function is not implemented in your VHF–DSC radio, an individual routine call could be made (except in the United Kingdom, where the usage of an allships urgency call is recommended).
Distress relay call sent by voice As always, it is necessary to retransmit information also by voice on channel 16 to the relevant coast station, so that it is heard by other vessels in the vicinity. The distress relay call sent by radiotelephony should be given in the following form: the distress signal MAYDAY RELAY, spoken three times; All stations or coast station name, as appropriate, spoken three times; the words This is; the name of the relaying station, spoken three times; the call sign or other identification of the relaying station; the MMSI of the relaying station (not the vessel in distress). This call must be followed by a distress message that will, as far as possible, repeat the information contained in the original distress alert or distress message. If the station in distress cannot be identified, you can use such terms as unidentified trawler, motor yacht – name is unknown, etc. Thus (with CROSS Corsen an MRCC near Brest, France): MAYDAY RELAY, MAYDAY RELAY, MAYDAY RELAY.
CROSS Corsen, CROSS Corsen, CROSS Corsen. This is Mercator, Mercator, Mercator, call sign Hotel Bravo Yankee Three Four Five Six Zero Zero, MMSI number 2 6 9 3 4 5 6 0 0. Received the following distress call by DSC and on channel 16: Silver Crest, Silver Crest, Silver Crest, call sign Papa Charlie Three Three Four Nine. MMSI number 2 4 4 2 6 0 2 4 6. Position 4 9 degrees 1 9 minutes North, 0 0 2 degrees 4 3 minutes West, time 2 0 0 5 UTC, The vessel is flooding. They require immediate assistance. Over. Occasionally an MRCC makes a distress relay call itself with its more powerful transmitter, addressed to, as appropriate, all ships, a selected group of ships, or a particular ship. A ship station in receipt of a shore-to-ship distress relay call should establish communication as directed and render such assistance as is required and appropriate.
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Distress acknowledgement In order to ensure that no unnecessary delay occurs before the shore-based authorities become aware of a distress incident, the acknowledgement by DSC to a distress alert sent by DSC will normally only be made by a coast station or a rescue co-ordination centre. An acknowledgement by DSC will cancel any further automated repetition of the distress alert using DSC. If no acknowledgement of the distress alert has arrived within 5 minutes, after relaying the distress call to an MRCC you might be asked to acknowledge recept of the alert and possibly undertake assistance. This acknowledgement of a distress alert or distress call is by voice for a small craft equipped with VHF–DSC Class D radio. The acknowledgement should be given in the following form: the distress signal MAYDAY; the name followed by the call sign, or the MMSI or other identification of the station in distress; the words This is; the name and call sign or other identification of the station acknowledging receipt; and the words RECEIVED MAYDAY. For example: MAYDAY,
Silver Crest, MMSI 4 4 2 6 0 2 4 6. This is Mercator, MMSI number 2 6 9 3 4 5 6 0 0. RECEIVED MAYDAY.
We are proceeding to your assistance, ETA at distress position within 45 minutes. Over. The acknowledgement contains the words RECEIVED MAYDAY, and possibly any assistance you can offer.
Distress traffic A vessel in distress, broadcasting a distress alert or a MAYDAY call, automatically imposes general radio silence. During the period of radio silence, channel 16 must not be used for anything other than essential distress communications. Distress traffic consists of all messages relating to the immediate assistance required by the ship in distress, including search-and-rescue communications and on-scene communications. During a distress situation, you will hear other procedural words, such as SEELONCE MAYDAY, PRUDONCE and SEELONCE FEENEE, spoken as in French: silence Mayday, prudence and silence fini (finished).
Imposing radio silence If someone breaks radio silence, they are likely to get a sharp reprimand from the controlling station. It would sound like this: SEELONCE MAYDAY, this is CROSS Jobourg.
Out.
Another listening station not in control of the distress situation (your own vessel perhaps) may also impose silence, but should use the expression, SEELONCE DISTRESS, rather than SEELONCE MAYDAY. SEELONCE DISTRESS, this is yacht Mercator.
Out.
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Relaxing radio silence The station controlling these communications will decide when radio silence is relaxed or ended. The procedural word PRUDONCE (pronounced as in French prudence) signals a slight relaxation of the silence, allowing other necessary radio traffic on the distress channel. The message would sound like this: MAYDAY.
All stations, all stations, all stations. This is CROSS Jobourg, time 2 1 0 5 UTC. Yacht Silver Crest, MMSI number 2 4 4 2 6 0 2 4 6. PRUDONCE.
Out.
Finishing radio silence Radio silence would be maintained until the distress situation is cleared. The station in control of distress traffic uses the expression SEELONCE FEENEE to advise that normal traffic may now continue on the distress channel 16 – it is back to normal working. MAYDAY,
All stations, all stations, all stations. This is CROSS Jobourg, CROSS Jobourg, CROSS Jobourg, time 2 1 1 5 UTC, MMSI number 2 4 4 2 6 0 2 4 6, Yacht Silver Crest, SEELONCE FEENEE.
Out.
The time indicated is the message time. SEELONCE FEENEE is pronounced as the French expression silence fini (silence finished).
On-scene communications On-scene communications are defined as those of Search and Rescue (SAR), exchanged between the ship in distress and ships and aircraft in the vicinity of the distress. Communications are carried out by radiotelephony on VHF channel 16, and on channel 06 by any aircraft involved, or another simplex ship-to-ship channel specified by the controlling station. Calls must be prefixed by the distress signal MAYDAY. A handheld VHF radio could play a significant role in on-scene communications. Such a device can be used in the cockpit, in a life-raft, in rough conditions and in the most difficult of situations.
Cancellation of an inadvertent distress alert If for some reason you send a distress alert in error, you should call the coastguard (MRCC) immediately and inform them. If you have children, it is very important that you emphasise the likely consequences of playing with a VHF–DSC set. An inadvertent distress alert can be cancelled by DSC if the DSC equipment is capable of transmitting a self cancel (a distress acknowledgement where the transmitting MMSI and the ship in distress MMSI are the same). New Class D marine VHF radios should be capable of this function. If not, the automatic repetitions of false alerts by DSC should be avoided by switching the VHF–DSC radio off and then on again. In all cases, cancellations must also be transmitted by radiotelephony on channel 16 using the procedure illustrated by the following example:
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MAYDAY,
All stations, all stations, all stations. This is Obelix, Obelix, Obelix, call sign Lima Alfa Nine Two Nine Four. MMSI number 2 5 7 6 1 6 8 3 0. PLEASE CANCEL MY DISTRESS ALERT OF 0 7 4 2 UTC.
Out.
Monitor channel 16, and respond to any communications concerning that distress transmission as appropriate.
Transmitting a distress alert or an urgency call In distress situations, deciding whether to transmit a distress call is a matter for the skipper’s judgement. For instance in a man overboard (MOB) situation, you might have a casualty in sight, it might be a fine sunny day and you might be reasonably confident that you and your crew can make a recovery. But if there is any doubt that you need immediate help, if the casualty is not wearing a lifejacket and the sea is cold, things could go wrong. You can always cancel a MAYDAY, but making the call 15 minutes later could be the difference between life and death for the person in the water. When the sending of a distress alert is not justified – for instance, your yacht is severely disabled but you do not require immediate assistance – send an urgency call.
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Urgency communications Urgency is a lesser degree of emergency concerning the safety of a vessel or person where a very urgent message is to be transmitted to request assistance. The danger is not imminent but assistance is required because of a serious problem. Urgency is when a vessel may not truly be in distress but has a problem that may potentially lead to a distress situation. Urgency applies when (for instance) a boat is taking in water but not yet sinking, or has engine failure in strong currents and is some distance from shore, or a crew member has been injured and needs treatment but whose life is not threatened. Urgency communications take priority over all other communications except those concerned with distress. An urgency call may only be sent on the authority of the master or skipper. An urgency communication by a VHF–DSC comprises an urgency announcement, sent by DSC on channel 70, followed by a voice urgency call and urgency message, generally on channel 16 starting with the urgency signal PAN PAN (RR Article 33). The urgency announcement is a digital selective call signified by the generic term Urgency call on most VHF–DSC radios. Urgency calls are transmitted normally by ship stations to request urgent assistance. Another ship will be able to come to your assistance, or a coast radio station will transmit a request to the search-and-rescue services if those are needed. Occasionally, a coast radio station will itself transmit an urgency call – for instance in relation to a vessel reported overdue, asking all ships to keep a sharp lookout and report any sighting. Urgency communications may be addressed either to all stations or to a particular station. Small craft fitted with VHF–DSC equipment with a Class D controller always transmit urgency announcements to all stations.
Urgency announcement sent by DSC While in DSC mode, select Call and the Type of call, as follows: Scroll through to All ships Urgency call. Channel 16 is selected automatically, as the subsequent urgent voice communications have to be made on channel 16. Initiate the call via Send. Confirm via the key to transmit. The transmission takes about half a second on channel 70 with high power of 25 W. The transmitted digital sequence contains the MMSI of the station and the channel for subsequent voice communications, namely channel 16. The position of the ship is not transmitted in an urgency call by DSC (this is regrettable – but when DSC was defined, GPS was not available). All ship stations and coast stations within range receive information via their VHF–DSC radios, with an accompanying audible alarm. The received call appears on the display as follows:
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Distress, Urgency and Safety communications The ship station with MMSI 235028894 is announcing an urgent call and message on channel 16. Press the Stop soft key to mute the alarm, then monitor channel 16 for the voice urgency call.
All the VHF–DSC radios within range tune to channel 16, either automatically or after use of the OK soft key. No acknowledgement is expected for an all-ships urgency call. The radio operator of the vessel in need of urgent assistance should wait 15 seconds before sending a voice call and message on channel 16 to give more details (see below). Whether DSC is fitted or not, the format of the voice communication is identical except that the vessel’s MMSI is not given.
Urgency call and message (voice) The urgency signal consists of the words PAN PAN, pronounced as the French words panne panne meaning breakdown or problem (pronounced something like PAHN-PAHN). The urgency call should consist of: the urgency signal PAN PAN, spoken three times; the name of the called station or All stations, spoken three times; the words This is; the name of the station transmitting the urgency message, spoken three times; the call sign or any other identification; and the MMSI (if the initial announcement has been sent by DSC). This is followed by the urgency message itself or, first, by details of the channel to be used for the message in the case where a working channel is to be used. The urgency call and urgency message are normally transmitted on VHF channel 16, the distress, urgency and safety traffic channel. However, the urgency message should be transmitted on a working channel in the case of a long message, or a call for medical assistance, or in areas of heavy traffic when the message is being repeated. A coast station will probably ask the message sender to switch to one of its duplex working channels, eg 25, 79 or 82. Such emergency messages are normally addressed to all stations, in high-power mode. The urgency message is free format but always has to start with stating the position of the vessel; the nature of the problem (dismasted, engine failure, lost dangerous cargo, etc); the kind of assistance required; and any other useful information, such as the number of crew aboard. The message is ended with Over, an invitation to reply. Thus: PAN PAN, PAN PAN, PAN PAN.
ALL STATIONS, ALL STATIONS, ALL STATIONS or {name of the called station} THIS IS {name of the vessel}, {name of the vessel}, {name of the vessel}, CALL SIGN {call sign of the vessel}, MMSI {MMSI of the vessel}. POSITION {vessel’s position}. {nature of problem, assistance required, other useful information} OVER. The position of the ship must be transmitted in the urgency message as it is not included in the initial urgency announcement sent by DSC. If your ship is drifting, the rate and direction of drift could be stated and also the time of the position given. Ships receiving an urgency call must listen to the emergency message on channel 16 and assess whether they can offer assistance. If assistance is possible, the radio operator should contact the rescue co-ordination centre and offer that assistance.
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Although the PAN PAN call will not necessarily impose general radio silence, you should expect an immediate response from one or more stations called. Probably the nearest coast radio station or the coastguard will respond.
Urgency communications – example Example: You are on board the fishing vessel Trident, on the way to St Helier (Jersey). In the Western Passage, the vessel’s propeller has been entangled in a heavy fishing net and its engine does not therefore function any more. The current of 3.5 knots is pushing the vessel towards the rocks of Demi-de-Pas. You have to ask for towing assistance, because within 30 minutes Trident will broken on the rocks of Demi-de-Pas. You send an urgency call by DSC to all stations, and then a voice call on channel 16.
Urgency announcement sent by DSC Your VHF radio is in dual-watch mode on channel 14 in order to monitor St Helier Port Control. You switch to DSC mode and select Call to make an urgency announcement: Select the Type of digital call: All ships Urgency call. The voice communication will follow on channel 16. Initiate the call by Send, and then confirm via the
key.
In a few seconds, channel 16 is selected automatically with high power of 25 watts.
The following calling sequence is transmitted by DSC:
Ship stations and coast stations within range will receive the call and the alarm will ring on their VHF–DSC radio.
Urgency call and message by voice Trident will use a complete identification of the station, including its MMSI number, so that stations receiving the voice call will know that the vessel is the one that had transmitted the urgency call by DSC a few seconds earlier. Trident would say:
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PAN PAN, PAN PAN, PAN PAN.
All stations, all stations, all stations. This is fishing vessel Trident, Trident, Trident, call sign Mike Juliett Victor Charlie Three. MMSI number 2 3 5 0 2 8 8 9 4. My position 2 cables south of Noiremont Point, 4 9 degrees 0 9 minutes North, 0 0 2 degrees 1 1 minutes West. Our propeller is engaged in a heavy fishing net, our engine is disabled. We require tug assistance. Over. The exact GPS position of Trident is given in the message only after the ship has been more generally described as located relative to a known and charted place, Noirmont Point. This can be a useful redundancy in voice radiotelephony.
A coast radio station or a ship in the vicinity answers the request for assistance by radiotelephony (voice) on channel 16. A response from Jersey Radio is received within a few seconds, requesting the damaged vessel to switch to working channel 25: Trident, Trident, this is Jersey Radio. Received your urgency message. Please switch to channel twenty-five, two five. Over. Continuing on channel 25, Jersey Radio will coordinate a tow operation for Trident.
Urgent medical assistance An important domain of urgency communication is when urgent medical assistance is needed. In such circumstances, an urgency announcement is first sent by DSC, followed by a PAN PAN voice call to the nearest coast radio station or rescue co-ordination centre, which will connect the requesting station free of charge to a physician in the radiomedical service of a specialist hospital. The physician, who has been specially trained to give advice by radio to casualties at sea, will ask questions about the sick or injured person (temperature, blood pressure, pulse and respiratory rates, plus an accurate description of symptoms). The physician might decide on the need for evacuation to hospital by lifeboat or helicopter. A doctor onboard another vessel might sometimes be involved in radiomedical assistance. The format of urgency communications for medical assistance is exactly as explained above for general urgency assistance. It is wrong to add the word MEDICO (as was heard some time ago), because somebody could misunderstand it for PAN PAN MEDICAL,
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which is used for identifying medical transportations necessary in an armed conflict and which are protected by the 1949 Geneva Conventions. Many coast radio stations specifically offer radiomedical services as indicated in the ITU’s List of Coast Stations or in the Admiralty List of Radio Signals. Example: the Swedish yacht Amorina, cruising to the south-west of Alderney, needs urgent medical assistance. Its position is 49º42' N 002º17' W. Amorina is equipped with a VHF–DSC radio, so it will make the following call: Select All ships Urgency call. Subsequent voice communications will be on channel 16. Call is initiated via Send and confirmed via the
key.
Channel 16 is selected automatically with high power. Amorina continues with an urgency call and urgency message requesting medical assistance: PAN PAN, PAN PAN, PAN PAN.
All stations, all stations, all stations. This is Swedish yacht Amorina, Amorina, Amorina, call sign Sierra Hotel Uniform Tango. MMSI number 2 6 5 5 1 3 9 9 0. Position West of Alderney, in the Swinge. 4 9 degrees 4 2 minutes North, 0 0 2 degrees 1 7 minutes West. We have a crew member with a serious eye injury and unconscious. We need urgent medical assistance. Over. While normally no details should be given about the nature of medical problems in this initial request addressed to the MRCC and to the ships in vicinity, an indication might be appropriate in some cases (as in the example above). The nearest rescue co-ordination centre, CROSS Jobourg, answers immediately and nominates a working channel. Amorina, this is CROSS Jobourg. Received your Pan Pan. Please switch to channel 79, 7 9. I will connect you to a doctor. Over. The position of the ship that requires medical care can be very useful, including finding a doctor close enough or to organise an evacuation when this becomes necessary. CROSS Jobourg usually works with the French telemedical service, the Centre de Consultations Médicales Maritimes in Toulouse. Amorina being in sea area A1, MRSC Brixham (78 nm), Jersey Radio (31 nm) and CROSS Jobourg (15 nm) should be within radio range. In addition, these cost stations have remote antenna sites even closer. These MRCCs will surely receive the request for urgent medical assistance of Amorina.
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Urgency cancellation When an urgency announcement or call and message has been transmitted to more than one station and action is no longer required, an urgency cancellation should be sent by the station responsible for its transmission. PAN PAN, PAN PAN, PAN PAN.
All stations, all stations, all stations. This is Trident, Trident, Trident, call sign Mike Juliett Victor Charlie Three. MMSI number 2 3 5 0 2 8 8 9 4.
PLEASE CANCEL MY URGENCY MESSAGE OF 0 6 5 7 UTC.
Out.
Safety communications Safety communications are generally associated with a notification of a navigational hazard or meteorological warning. When using Distress or Urgency calls, you are asking for assistance, either for yourself or for someone else. Safety calls are used to warn other vessels about a potential hazard to navigation or sever weather. Safety calls and messages are usually originated from a rescue co-ordination centre (RCC), coastguard or coast radio station. However, they can also be issued by vessels at sea when reporting navigational hazards they have encountered. A safety message usually contains information about an overdue vessel, debris in the water, loss of a navigational aid, or important meteorological information. Safety communications have priority over all other communications, except those for distress and urgency incidents. A safety communication by VHF–DSC comprises a safety announcement, sent by DSC on channel 70, followed by a voice safety call on channel 16 starting with the safety signal SECURITE, and by a safety message that is usually on a working channel. The procedural word is SECURITE (sécurité, French for safety, pronounced SAY-CURE-E-TAY). The form of safety communications is defined by the RR Article 33. Safety calls from a coast station are sometimes preceded by a safety announcement by DSC, but most often they are not because there is concern about congestion in some areas. Safety messages transmitted by coast stations in accordance with a predefined timetable should not be announced by DSC, and safety messages that only concern vessels sailing in the vicinity should be made using radiotelephony procedures. The Safety call is broadcast on channel 16, like this: SECURITE, SECURITE, SECURITE.
All stations, all stations, all stations. This is Solent Coastguard, Solent Coastguard. For gale warning listen channel 23, 2 3. In this case, switching to channel 23, you would then hear the gale warning. If you see a navigational hazard yourself, you should report the matter to the rescue coordination centre or coastguard on channel 16. It could be a message concerning the safety of navigation generally – such as notice of a drifting pallet, or an unlit buoy. If you cannot get through to the rescue co-ordination centre or coastguard, you should put out an all-ships warning on channel 16, like this:
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SECURITE, SECURITE, SECURITE.
All ships, all ships, all ships. This is yacht Moonlight, Moonlight, Moonlight. Drifting container half submerged seen East of Guernsey, South Lower Heads 3 cables. Position 4 9 degrees 2 5 decimal 8 minutes North, 0 0 2 degrees 2 8 decimal 6 minutes West time 2 1 4 7 UTC. Drifting North-East 2 knots. Out. Safety communications may be addressed either to all stations or to a particular station. Small craft fitted with a VHF–DSC radio with a Class D controller always transmit a safety announcement to all stations first, followed by a Safety call and a Safety message.
Safety announcement sent by DSC While in DSC mode, select Call and the Type of call, as follows: Scroll to All ships Safety call. The call is addressed to all stations and transmitted on channel 70 with high power. Initiate the transmission by Send. The subsequent voice call will be on channel 16 – there is no option to select another channel. Confirm via the
key to transmit.
A safety announcement contains the MMSI number of the calling station and the channel number for subsequent voice communication (usually channel 16, but some DSC controllers allow selection of an inter-ship channel). The position of the ship is not transmitted. The transceiver switches automatically to channel 16 to transmit a voice safety call and message. Power of transmission is 25 watts.
All VHF–DSC radios in range will receive an audible alarm and will automatically switch to channel 16. There is no acknowledgement expected to an all-ships safety call.
Safety call and message (voice) The complete safety call should consist of: the safety signal SECURITE, spoken three times; the name of the called station or All stations, spoken three times; the words This is; the name of the station transmitting the safety message, spoken three times; the call sign or any other identification; and the MMSI (if the initial announcement was sent by DSC). This is followed by the Safety message or, first, the details of the channel to be used for the message in the case where a working channel is to be used. The safety message
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should, where practicable, be transmitted on a working channel; a suitable indication to this effect should be made at the end of the safety call. First alternative: Safety call on channel 16 and instructions to change to a working channel: SECURITE, SECURITE, SECURITE.
ALL STATIONS, ALL STATIONS, ALL STATIONS or {name of the called station} THIS IS {name of the vessel}, {name of the vessel}, {name of the vessel}, CALL SIGN {call sign of the vessel}, MMSI {MMSI of the vessel}. Please switch to {working channel} to listen … The safety message is transmitted on the working channel: {the text of the safety message}. OUT. Second alternative: Safety call and Safety message on the selected working channel: SECURITE, SECURITE, SECURITE.
ALL STATIONS, ALL STATIONS, ALL STATIONS {or name of the called station} THIS IS {name of the vessel}, {name of the vessel}, {name of the vessel}, CALL SIGN {call sign of the vessel}, spelled MMSI {MMSI of the vessel}. {the text of the safety message}. OUT. The text of the safety message could well include the vessel’s position or the position of an obstruction.
Safety call by a ship station – example Example: on board the French fishing vessel Allegro, at the mouth of the Gironde estuary in position 45°36.4' N, 001°30.2' W, on February 13 at 17h50 you see drifting logs which are judged to be dangerous to navigation. Switch to DSC mode and select Call then the Type of the call: Scroll to All ships Safety call. The subsequent voice communication will be sent on channel 16. Time is now 16:52 UTC. Initiate by Send and then confirm by the
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The following calling sequence is transmitted by DSC:
Allegro’s safety call and message on channel 16 would be: SECURITE, SECURITE, SECURITE.
All stations, all stations, all stations. This is Allegro, Allegro, Allegro, call sign Foxtrot Zulu Charlie Mike. MMSI 2 2 7 8 2 8 0 0 0. Position 4 5 degrees 3 6 decimal 4 minutes North, 0 0 1 degrees 3 0 decimal 2 minutes West time 16:52 UTC. Drifting logs sighted in our position. Dangerous for shipping. Vessels in vicinity keep sharp lookout. Out. As logs drift with the current, the UTC time when the position was accurate is specified. Station CROSS Etel, which has sites all along the Atlantic coast of France, could answer on channel 16 if additional information is thought necessary: Allegro, Allegro, Allegro, This is CROSS Etel, CROSS Etel, CROSS Etel. Good afternoon. Thanks for your security message. Please switch to channel 79, channel 7 9. Over.
CROSS Etel can contact Allegro by a DSC routine call using the MMSI number, unless the station prefers a communication on channel 16. CROSS Etel will transmit any additional information to the coordination services of Maritime Safety Information (MSI), which in turn will broadcast a navigational warning on VHF and on 2,182 kHz on MF as well as by Navtex.
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Safety call by a coast station – example The DSC safety announcement received from CROSS Etel would be like this: An All ships safety call is known to be from a coast station because the MMSI number starts with 00. Silence the alarm by Stop. The VHF radio will switch automatically to channel 16. CROSS Etel will transmit the following on channel 16: SECURITE, SECURITE, SECURITE.
All stations, all stations, all stations. This is CROSS Etel, CROSS Etel, CROSS Etel. Navigational warning number 1 8. Please switch to channel 79, channel 7 9. This message allows changing channel by all ships in the area, with communications continuing on the nominated working channel 79. SECURITE, SECURITE, SECURITE.
All stations, all stations, all stations. This is CROSS Etel, CROSS Etel, CROSS Etel. Navigational warning number 1 8. Floating obstruction latitude 4 5 degrees 3 6 decimal 4 minutes North, longitude 0 0 1 degrees 3 0 decimal 2 minutes West. Dangerous for shipping. All ships keep a sharp lookout and report sightings. Out. Note that navigational warnings are numbered (18 in our example).
Safety broadcasts Within the framework of Maritime Safety Information broadcasts, coastal and local navigational warnings are also promulgated by VHF by coast stations – usually by coastguard authorities or MRCCs. These warning cover navigational aids, lights, buoys, wrecks, naval exercises, SAR operations, cable laying, piracy, etc. Other hazards (such as submarines operating just below the surface, gunnery and missile firing, and underwater explosions) are also the subject of navigational warnings.
Urgent warnings Urgent warnings are broadcast on VHF channel 16 as soon as possible after receipt, usually preceded by an all-ships safety call by DSC. Urgent warnings are then repeated on the hour and half-hour until cancelled.
Regular navigational warnings Regular navigational warnings are broadcast usually every 3 or 4 hours using the relevant coast station’s assigned VHF working channels – for instance Netherlands Coastguard on channel 23 or 83, CROSS stations in France on channel 79 or 80, stations in Portugal (including the Azores) on channel 11 in English and Portuguese, etc. Usually, regular navigational warnings are not preceded by a DSC call in order to avoid congestion, but in some countries they are announced by a call on channel 16. Look up your nautical almanac or other publications for broadcasting schedules.
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Weather forecasts There are many good sources of weather forecast and strong-wind warnings for mariners: the internet, television, FM and AM radio, professional forecaster services via telephone or SMS text message, etc. Marine VHF radio is an extremely cost-effective way of having free access to weather forecast information. MRCCs routinely broadcast Maritime Safety Information, including gale and strong-wind warnings. Forecasts for an area usually cover 2 or 3 days. The VHF working channels and local times of broadcast are published in nautical almanacs and other widely distributed publications. Recorded weather forecasts There are a growing number of coastal areas where a recorded weather forecast is broadcast continuously on a VHF working channel. The working channels are usually some of the normal international VHF channels – for example in Italy channel 68 and in France channel 23, 24, 25 or 63. In the United States and Canada, special receive-only weather channels exist (see Appendix 3) for transmitting continuous local and coastal marine forecasts.
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Quiz 6 Questions 01
Which system provides an international communications network to assist vessels in distress?
02
Are vessels equipped only with traditional VHF radios or handheld VHF sets without DSC functions excluded from the GMDSS?
03
What are the priorities for messages concerned with safety of life at sea?
04
Under what circumstances would you transmit a distress alert or a distress call and message?
05
How do you make a fast distress alert if you have a fixed-mount VHF–DSC radio?
06
Is the term distress alert synonymous with the term distress call?
07
To whom are DSC distress alerts and radiotelephony distress calls addressed?
08
Whose authority is required before sending a distress alert or using the distress signal MAYDAY?
09
What are the three details of a distress situation that must included in a distress alert?
10
What other detail can be included in a distress alert?
11
How do you know whether a distress alert has been received by a coast station (MRCC or coastguard)?
12
Can you transmit a MAYDAY call if no acknowledgement has been received for your distress alert by DSC?
13
What sequence is used when transmitting a distress message on behalf of another station by a VHF–DSC radio?
14
How can you cancel a false distress alert transmitted by a VHF–DSC radio?
15
What is meant by the term radio silence?
16
How is the end of distress traffic notified to the stations in the area concerned?
17
What does it means if you hear PAN PAN spoken 3 times on channel 16?
18
By which type of call can one ask for medical assistance?
19
What is the safety signal given in a safety call?
20
Which stations most often transmit safety calls?
Answers on next page.
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Answers 01
The Global Maritime Distress and Safety System (GMDSS), since 1999.
02
Marine VHF radios should have DSC functions to conform with GMDSS carrying requirements, but the voice procedures are applicable to all ship stations.
03
Priority of messages: 1, distress; 2, urgency; 3, safety.
04
When, in the opinion of the master, a vessel or a person is under the threat of grave and imminent danger, for which immediate assistance is required.
05
Press the red DISTRESS button on your VHF–DSC radio and hold it down for five seconds. It must be followed by a voice MAYDAY call and message.
06
No. A distress alert is sent by Digital Selective Calling (DSC) and a distress call is by radiotelephony (voice) starting with the distress signal MAYDAY.
07
Distress alerts by DSC and distress calls by voice are never addressed to a particular station; these calls are used to alert all stations.
08
A distess alert or distress call should only be sent on the authority of the master (captain, skipper, etc) or other person responsible for the ship.
09
The MMSI number of the ship in distress, her position, and the UTC time when the position was valid.
10
If time allows, the nature of the distress should be included in a distress alert, by scrolling through the available distress categories.
11
The coast station keeps continuous watch on VHF channel 70 and will send an acknowledgement immediately by DSC to all stations within range.
12
Yes. If for whatever reason no acknowledgement has been received after 15 seconds’ wait, a voice distress call and distress message should be transmitted.
13
A distress relay call is sent by DSC and individually addressed to a coast station or rescue co-ordination centre A MAYDAY RELAY call should follow by radiotelephony.
14
By switching the VHF radio off and then on again (to terminate repeat messages) and by transmitting on channel 16 a message including PLEASE CANCEL MY DISTRESS ALERT OF {UTC time}.
15
Stations not directly involved with ongoing distress communications may not transmit on the distress channel, to prevent interference to distress traffic.
16
The coordinating station – usually an MRCC – broadcasts the message SEELONCE FEENEE (pronounced as the French expression silence fini).
17
The station is preparing to transmit an urgency message, possibly concerning the safety of a ship or person.
18
By an urgency announcement by DSC, and the subsequent PAN PAN message stating I require medical assistance.
19
The word SECURITE spoken three times at the beginning of a safety call.
20
Safety calls are most often transmitted by MRCCs concerning navigational safety, but ships can also announce such dangers to navigation.