SOS was chosen as the universal distress signal by the International Radio Telegraph Convention of July 1908 because this combination of three dots followed by three dashes followed by three dots (...---...), was easy to send and easily recognized, especially since they were usually sent as a nine-character signal, which stood out against the background of three-character Morse Code letters. The letters themselves are meaningless. From John A. Fleming’s 1910 second edition of The Principles of Electric Wave Telegraphy:
This signal, S,O,S, has superseded the Marconi Company’s original high sea cry for help, which was C,Q,D.
SOS is another “word” with a false acronymic origin. SOS does not stand for Save Our Souls, Save Our Ship, Stop Other Signals, Sure Of Sinking, or any other phrase. The first recorded mention of the false acronymic origin is in reference to the Titanic sinking of 1912, which may account for the wide spread and endurance of the myth. From the New York Times of 16 April 1912, a misstatement by a man who should have known better:
“I don’t know the name of the wireless operator aboard the Titanic, but he probably used ‘S.O.S.,’ ‘C.Q.D.,” and everything else he could think of.”
“Yes," [Marconi] went on in answer to a question, “the ‘C.Q.D.’ was the old Marconi code call for a ship in distress, but the later signal was substituted in the international code. The ‘C.Q.’ was the call for all stations to attend, and the ‘D.’ was danger. The ‘S.O.S.,’ the operators say, means ‘Save our souls.’”
Not only was Marconi wrong about the meaning of SOS, but the D in CQD is not documented to stand for danger, distress or anything else either.
(Source: Oxford English Dictionary, 2nd Edition; Proquest Historical New York Times)
Copyright 1997-2015, by David Wilton