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Glossary of Terms
This is an emergency procedure word used internationally as a distress signal in voice procedure radio communications. It
derives from the French venez m'aider, meaning "come help me".
It is used to signal a life-threatening emergency primarily by mariners and aviators, but in some countries local organizations
such as police forces, firefighters, and transportation organizations also use the term. The call is always given three
times in a row ("MAYDAY MAYDAY MAYDAY") to prevent mistaking it for some similar-sounding phrase under noisy conditions,
and to distinguish an actual MAYDAY call from a message about a MAYDAY call.
Making a false distress call in the United States is a federal crime carrying sanctions of up to six years imprisonment,
and a fine of $250,000.
If a MAYDAY call cannot be sent because a radio is not available a variety of other distress signals and calls for help can
be used. A MAYDAY can be sent on behalf of one vessel by another, using a convention called a MAYDAY RELAY.
A MAYDAY RELAY call is made by one vessel on behalf of a different vessel which is in distress. If a vessel makes a
MAYDAY call and it is not acknowledged by the Coastguard after a single repetition and a two-minute wait, then a vessel receiving
the MAYDAY call should attempt to contact the Coastguard on behalf of the MAYDAY vessel by broadcasting a MAYDAY RELAY.
A MAYDAY RELAY call should use the callsign of the transmitting vessel but give the name and position of the MAYDAY vessel.
MAYDAY RELAY calls can be used to summon help for a vessel which is either too far offshore to contact the coastguard directly
or without radio capabilities (though most vessels above a certain size or crew complement are legally required to carry
two-way radio equipment, which could have potentially been damaged or destroyed).
PAN-PAN (from the French: panne – a breakdown) indicates an urgent situation of a lower order than a "grave and imminent
threat requiring immediate assistance", such as a mechanical breakdown or a medical problem. The suffix medico
used to be added by vessels in UK waters to indicate a medical problem (PAN-PAN MEDICO repeated three times), or by aircraft
declaring a non-life-threatening medical emergency of a passenger in flight, or those operating as protected medical transport
in accordance with the Geneva Conventions. "PAN-PAN MEDICO" is no longer in official use.
In radiotelephone communications, a call of three repetitions of PAN-PAN is used to signify that there is an urgency on board
a boat, ship, aircraft, or other vehicle but that, for the time being at least, there is no immediate danger to anyone's
life or to the vessel itself. This is referred to as a state of urgency. This is distinct from a MAYDAY call,
which means that there is imminent danger to life or to the continued viability of the vessel itself. Thus "PAN-PAN" informs
potential rescuers (including emergency services and other craft in the area) that a safety problem exists whereas "MAYDAY" will
call upon them to drop all other activities and immediately initiate a rescue attempt.
The correct usage is "PAN-PAN, PAN-PAN, PAN-PAN", followed by the intended recipient of the message, either "All
Stations, All Stations, All Stations" or a specific station, "Vancouver Coast Guard Radio, Vancouver Coast Guard
Radio, Vancouver Coast Guard Radio", the identification of the craft, its position, the nature of the problem and the
type of assistance or advice required, if any. An equivalent Morse Code signal used to be "X X X", with
each letter sent distinctly. It is also correct to use "PAN-PAN" as a preface if relaying a "MAYDAY" call
from another station that is out of range of the station they are trying to contact. This is common in aviation VHF
communications but not in nautical VHF communications.
Examples of the correct use of a "PAN-PAN" call from a boat or ship may include the following cases, provided
the skipper or master remains confident that they can handle the situation and that there is no current danger to the life
of any person or to the safety of the vessel itself.
Once the urgent situation which led to the PAN-PAN broadcast has been resolved or contended with, conventional practice is
for the station that initiated the PAN-PAN call to make a follow-up broadcast to All Stations, informing them that the urgent
situation no longer exists.
A call that originates as a "PAN-PAN" signal might be followed by a MAYDAY distress call if the situation deteriorates
to the point of "grave and imminent danger", thus warranting immediate action (intervention, assistance, response)
on the part of listeners in accordance with standard operating practices for distress signaling.
Fouled propeller, engine failure or out of fuel
Provided the vessel is now either anchored or under sail and safe from any immediate danger of collision or stranding. The
crew may be planning to clear the propeller, refuel from an onboard supply, hoist sail or use some other alternative propulsion.
Alternatively, as part of the "PAN-PAN" call, the skipper may request a tow from a suitable vessel, if possible,
but without immediate urgency.
Small fire on board - now extinguished
Fire can be very dangerous afloat but if it was small and contained and is now certainly put out without injury to any crew,
then a "PAN-PAN" call is appropriate to warn others that investigations are underway to establish the extent of
the damage, clear the smoke from below and hopefully re-establish passage as soon as possible.
Unsure of position
Provided there is no apparent danger of stranding or hitting rocks, a "PAN-PAN" call on marine VHF radio may allow
nearby coast-stations and perhaps other vessels to triangulate the source of the transmissions and provide the skipper with
both a fix and perhaps some advice on the best course to steer to reach a safe haven.
If safely recovering a person overboard, a "PAN-PAN" call on VHF makes other nearby vessels aware of the situation
and ensures that they keep a sharp lookout, avoid coming too close, and avoid excessive wake or otherwise interfering. It
also alerts them to the fact that the recovery vessel is maneuvering for urgent life-saving and is therefore 'restricted
in her ability to maneuver' in accordance with the International Regulations for Preventing Collisions at Sea (COLREGS).
If the recovery vessel has lost sight of the person overboard, if the person overboard loses consciousness, if there is a
danger of hypothermia or any other grave risk to life, then a MAYDAY call is more appropriate so that other nearby vessels
may offer help with the search and recovery, rather than keeping clear.
The US or Canadian Coast Guard (and likely similar maritime safety agencies in other countries) issue "urgent marine
information broadcasts" concerning vessels that have been reported overdue, as part of the process of a 'communications
search' or 'pre-com' phase of uncertain, possible distress, as determined under the authority of a maritime rescue co-ordination
centre or joint maritime-aeronautical rescue co-ordination centre. The message content, a description of the vessel
under the apprehension of being missing, its last known position and the date last heard from, and the supposed route or
passage plan of the vessel, is preceded by the prowords PAN-PAN and will be addressed to "all stations". Any
stations having information concerning the whereabouts of the named vessel are asked to communicate with and report same
to the nearest coast guard station.
Imminent Collision Alert
It may be warranted to urgently attempt to make radio contact with an approaching vessel that is running into danger or approaching
a dangerous close quarters situation and therefore at risk of colliding with one's own vessel, and warning the operator to
keep clear. This would be a 'bridge-to-bridge' communication and could be done in combination with sounding the "your
intentions are unclear or not understood" sound signal, which is 5 or more short horn or whistle blasts, the 'danger
signal'. A short blast is 1 second long, compared to a prolonged blast of 5 seconds duration under the COLREGS. An
urgent warning could also be given over the radio, for example, if the called vessel appears to be unaware that she is potentially
or at risk of endangering a person in a small boat or a person swimming, such as running them down. A loud hailer could
also be used along with a radio warning.
A "PAN-PAN MEDICO" call is appropriate if someone becomes injured or in need of medical help at sea. If the
vessel is heading to shore and wants to be met by an ambulance crew, the local Coast Guard station can arrange this. A
doctor or other trained medical advisor may also be available on the radio, perhaps by patching through via telephone from
ashore or from a nearby vessel. Again, if there is immediate risk to life, then a MAYDAY call is more appropriate. "PAN-PAN
MEDICO" is no longer in official use.
Marine Rescue Organizations, such as Coastal Patrol, Coast Guard & Search and Rescue listen on marine radio frequencies
for all distress calls including "PAN-PAN". These organizations can coordinate or assist and can relay such
calls to other stations that may be better able to do so.
One special case of "PAN-PAN" is to ask for medical advice. This is a normal "PAN-PAN" call including
a phrase such as "request medical advice" and the identification of the craft, its position and the nature of a
medical problem suffered by one of the passengers or crew. This type of call is specifically used in order to get a
doctor's advice for a medical problem that does not, in the current opinion of the skipper or master of the vessel, seem
to be life-threatening.
The phrase "PAN-PAN MEDICO" is used in some older reference books, but is no longer in official use.
Once patched through to a medical expert either on land or in another vessel, the radio operator will most likely be asked
to describe some detail of the symptoms and history of the condition and perhaps some medical history of the casualty too.
The doctor will, most likely, be able to recommend first aid treatment and give other advice to make the patient more comfortable,
using whatever resources are available on board. In some cases a decision may be made that the medical case is more
urgent than the skipper assumed, and so the call will be escalated to a 'MAYDAY' and receive immediate intervention by rescuers,
if at all possible.
(From the French...Pronounced: sécurité — safety) indicates a message about safety, such as a hazard to navigation or weather
When a marine radio transmission begins with "SÉCURITÉ, SÉCURITÉ, SÉCURITÉ", it means that what follows is important
safety information. The most common use of this is by coast radio stations before the broadcast of navigational warnings
and meteorological information.
It is normal practice to broadcast the SÉCURITÉ call itself on a distress and listening frequency such as VHF Channel 16
or MF 2182 kHz, and then change frequency to a working channel for the body of the messages. An equivalent Morse Code
signal is TTT, with each letter sent distinctly.
Although mostly used by coast radio stations, there is nothing to stop individual craft broadcasting their own SÉCURITÉ messages
where appropriate, for example, a yacht becalmed (rendered motionless for lack of wind), or any vessel adrift or unable to
maneuver near other craft or shipping lanes.
A typical format for an initial call is as follows:
SÉCURITÉ, SÉCURITÉ, SÉCURITÉ. All ships, all ships, all ships. This is station identifier. For a weather
forecast and important navigational warnings for the such-and-such area, please tune to frequency or channel number. This
is station identifier out.
(On channel 16)
SÉCURITÉ, SÉCURITÉ, SÉCURITÉ. All ships, all ships, all ships. This is Bravo Tango Sierra Uniform. For
an important navigational warnings for the Nonesuch Bay area, please tune to channel 40. This is Bravo Tango Sierra
(On channel 40)
SÉCURITÉ, SÉCURITÉ, SÉCURITÉ. All ships, all ships, all ships. This is Bravo Tango Sierra Uniform. Floating debris
and garbage found in the Nonesuch Bay area. Consider this as a surface navigation hazard. This is Bravo Tango
Sierra Uniform. Out.