The first spark Telegraphic emergency (FT- emergency ) in maritime history has been defined on 7 January 1904 by the Marconi Company as a distress signal. This was back in Morse code CQD: CQ (pronounced as "seek you" ) for " all " and D for " Distress "; colloquially called - designed " Come Quickly Danger ". The Morse code of CQD is: - • - • - ​​• - • •.

This first emergency call was complete: " CQD! At all! Distress! , Republic ' of unknown steamer rammed 26 nautical miles southwest of Nantucket. Help urgently needed. " Shortly before the British passenger liner RMS Republic of the White Star Line, with 742 people on board on the journey from New York to the Mediterranean in the dense fog had collided with the Lloyd Italiano steamer Florida. The Republic has been damaged on the port side at the level of passenger cabins. Three passengers were killed. The collision took place south of Martha 's Vineyard and 20 miles from Nantucket. The Florida with 800 emigrants for New York on board was able to separate from the Republic and subsequently took part in the rescue of passengers.

The Republic took water in the engine room and the entire technical operation collapsed. The ship was thus unable to move. The radio station was also paralyzed, because there was no electricity on board. However, the radio operator Jack Binns was able to connect the radio to the emergency batteries and provide the emergency call that was heard from the passenger ships La Lorraine, Baltic, Furnessia and New York. The people on board were taken from these ships on board and the next morning they tried to tow the disabled vessel to New York. Towards the Republic fell.

The call sign CQD had an indicative to an emergency meaning was, but listen out for radio operators very bad between other messages. Therefore, it was agreed on October 3, 1906 at the IFA consumer electronics conference in Berlin on the much easier to be recognized combination SOS ( three times short, three long, three short ) as a distress signal. This letter combination was chosen because of its easy recognition. It was interpreted as an abbreviation for " Save Our Souls " or " Save our Ship" until after the fact.

The word "Mayday " is used in radio communications in the maritime and aviation. It derives from the French " M'aidez " ( " Help Me " ) from.