From Academic Kids

Alternative meanings: May Day, Mayday (music).

Mayday is an emergency code word used internationally as a distress signal. Some people say that it was derived from the French Venez m'aider (come help me). This is likely because most other urgency calls like Seelonce or Securitay are also derived from French words. Many official sources, however, say that the word was made up -- like the distress signal SOS -- because it could not be mixed up with any other word, is easy to remember and can be understood even if the strength of the radio signal is weak.

It is used to signal a life-threatening emergency by many groups, such as police forces, the fire brigade, and transport organisations such as London Underground [1] (


Marine Mayday calls

The US Coast Guard definition of a Mayday situation is 'A vessel or aircraft are in grave and imminent danger and require immediate assistance', while the British Royal National Lifeboat Institution (RNLI) defines it as 'a situation where in the opinion of the Master a vessel, vehicle, aircraft or person is in grave and imminent danger and requires immediate assistance'. Examples of 'grave and imminent danger' in which a Mayday call would be appropriate are fire, explosion or sinking.

'Mayday' calls are made by radio, such as a ship or aircraft's VHF radio. Although a Mayday call will be understood irrespective of the radio frequency on which it is broadcast, first-line response organisations, such as the coastguard and air traffic control, monitor designated channels: marine VHF radio channel 16 and airband frequency 121.5 MHz, respectively. A Mayday call is the equivalent of a morse code SOS, or a telephone call to the emergency services.

The lifeboat at Brixham, south Devon, UK
The lifeboat at Brixham, south Devon, UK

When they receive a Mayday call, the coastguard may launch lifeboats and helicopters to assist the ship which is in trouble. Other ships which are nearby may divert course to assist the vessel broadcasting the Mayday.

Making a hoax Mayday call is a criminal act in many countries, because of the danger to the rescuers' lives that a search-and-rescue operation can create, as well as the very high costs of such rescue efforts. In the US, making a false distress call is a federal crime carrying sanctions of up to six years imprisonment, and a fine of $250,000[2] ( Hoax calls too, by their nature, devalue the use of the word Mayday, which rightly demands an instant and resource-intensive response.

The coastguard can be contacted in situations that are not emergencies (out of fuel, etc) by calling 'Coastguard, Coastguard, Coastguard, this is (name of vessel)', on VHF channel 16. In many countries however, special training and a licence are required to use a VHF radio legally (though in an emergency, anyone may use a VHF to summon help).

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 (see below).

Making a Mayday call

You must not make a Mayday call unless there is a real emergency, such as fire or sinking, or you may put lives in danger.

  1. Go to your VHF radio, switch it on, and set the power to High if you can.
  2. Select Channel 16 (156.8 MHz).
  3. Press the microphone button. (This might be labelled 'Push To Talk' or 'PTT'.)
  4. Hold down the microphone button and say
    • THIS IS (the boat's name, repeated three times)
    • MAYDAY (the boat's name)
    • Your location. You can read out the position from your GPS, or say something like 'one kilometre north of xxx harbour'. Geographic references are preferable to latitude and longitude which are easily misinterpreted. Repeat 3 times
    • The nature of the emergency (for example, 'we are on fire' or 'we are sinking') and assistance required (ex: we need pumps)
    • The number of people on board (for example, '5 people on board').
    • vessel identity repeated
    • OVER
  5. Then you should release the microphone button and wait for a response. You cannot hear what the Coastguard is saying to you unless you release the button.
  6. If you don't get a response after 20 seconds, you should repeat your Mayday call.
  7. As well as a Mayday call, you should depress the DISTRESS button on a DSC radio for 5 seconds. You should use other distress signals such as flags, flares, lights, smoke, and waving both arms outstretched. You should trigger your emergency position-indicating rescue beacon (EPIRB) as a last resort, if you have one.

Once you are in contact with the coastguard, you should listen carefully to the questions the coastguard asks you. These questions help the coastguard assess your situation and provide an appropriate rescue. Questions may include:

  • Description of the vessel
  • Details of any medical emergencies on board
  • The weather at your location
  • What emergency equipment your ship has (for example life jackets, flares, EPIRB, life raft).

The official way of making a Mayday call is slightly different around the world, but all English-speaking countries will understand you if you do it as described above.

Other urgent calls

Mayday is one of a number of words used internationally as radio code words, to signal important information. Senders of urgency calls are entitled to interrupt messages of lower priority. As with Mayday, the use of these terms without proper cause could render the user liable to civil and/or criminal charges.

Each of these urgency calls is usually repeated three times (eg "Pan pan, Pan pan, Pan pan").

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 this is not acknowledged by the coastguard after a single repetition and a two-minute wait, a vessel receiving the Mayday call should attempt to contact the coastguard on behalf of the Mayday vessel by broadcasting a Mayday Relay on their behalf.
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 too far offshore to contact the coastguard directly.


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 is added to indicate a medical problem (Pan-Pan medico, repeated three times).


Securite (pronounced 'Securitay') (from French securité) indicates a message about safety, such as a hazard to navigation.


The following calls may be made only by the coastguard or the vessel in distress:

Seelonce Mayday or Seelonce Distress mean that the channel may only be used by the vessel in distress and the coastguard (and any other vessels they ask for assistance in handling the emergency). The channel may not be used for normal working traffic until 'seelonce feenee' is broadcast.
The expressions Stop Transmitting - Distress and Stop Transmitting - Mayday are the aeronautical equivalents of Seelonce Mayday.
Seelonce Feenee (French: silence fini - silence finished) means that the emergency situation has been concluded and the channel may now be used normally. The word prudonce (prudence caution) can also be used to allow restricted working to resume on that channel.
Distress Traffic Ended is the aeronautical equivalent of seelence feenee.

See also

External links

fr:Mayday nl:Mayday


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