Mayday is an internationally recognized distress signal .
It derives from the French venez m’aider , meaning ‘come help me ‘. The Mayday call sign was originated in 1923 by Frederick Stanley Mockford (1897–1962)
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.
Examples of "grave and imminent danger" in which a mayday call would be appropriate include fire, explosion or sinking. Boats getting lost or boats running out of fuel is not considered grave and imminent danger.
Making a hoax Mayday call is a criminal act in many countries.