Mayday 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 organisations such as police forces, fire fighters, 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.
MAYDAY calls can be performed on any frequency. When a MAYDAY call is performed all other activity on that certain frequency should cease unless is contributing to the distress situation. A MAYDAY call can only be broadcasted in case of GRAVE and IMMINENT danger.
Despite the fact that the call can be made on any frequency, JRCC Larnaca and that SAR Units maintain continue listening on 2182 kHz (MF), Channel – 16 (156,8 MHz) on VHF/FM, and on 121,5 MHz and 234 MHz on aviation airband.
It is noted that the MAYDAY call is the equivalent of the “SOS” message in Morse code or a 112 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
Mayday Call should have the following structure:
NAME OF VESSEL (X3)
CALL SIGN OF VESSEL
NAME OF VESSEL
POSITION (preferably in latitude and longitude but if no time give it in relation to a known position)
NATURE OF DISTRESS
OTHER USEFUL INFORMATION
i.e. MAYDAY, MAYDAY, MAYDAY this is Orion, Orion, Orion Five Bravo Charlie X-ray Zulu
MAYDAY Orion Five Bravo Charlie X-ray Zulu
In position 34°29'42.28"N - 33°37'31.36"E (or 3 miles South East of Cape Greko)
Fire and Explosion in engine compartment and taking water, requesting immediate assistance
Six persons on board
OTHER USEFUL INFORMATION includes:
Type of Cargo (if any)
Weather, Visibility and sea condition
Time of abandonment
Number and type of survival craft
Number of persons abandoning/staying on board
Details of location aids in survival craft or sea