Let us start by busting a popular mainstream myth that the distress signal SOS stands for ‘Save our Souls’, as in really SOS, actually, stands for…nothing at all.
It is simply a continuous Morse code string of three dots, three dashes, and three dots all run together with no spaces or full stops (…—…), and it is, by far, not the first radio telegraphic distress code in use. At the beginning of the 20th century, when ships were getting equipped with wireless radio machines, different organisations and countries had their own distress signals.
For example, the U.S. Navy used NC, the Italians recommended the use of SSSDDD to signal an emergency, the main manufacturer of ship telegraph equipment, the Marconi Company, used CQD (derived from the earlier CQ code, used by telegraphers to address all stations at once); whereas the German Regulations for the Control of Spark Telegraphy of 1905 mandated that all German operators use SOE for all inquiry calls and SOS for distress, as recorded by The Electrician, on May 5, 1905: “German Regulations for the Control of Spark Telegraphy” which stated: “…—…, “Distress” signal (Notzeichen). This is to be repeated by a ship in distress until all other stations have stopped working.”
In 1906, at the second International Radiotelegraphic Convention in Berlin, the German SOS was chosen as the international distress signal, and went into effect on July 1, 1908, to be first recorded in use an year later by the Cunard liner SS Slavonia on July 10, 1909 during a shipwreck off the Azores, Portugal (two steamers went to the rescue after receiving the distress signal), followed by its use on August 11 1909, when the steamer SS Arapahoe broke a propeller off the coast of North Carolina.
Although the use of SOS was officially ratified in 1908 by all nations who met at the Berlin conference, except the United States, where it took some time to adopt the practice, the use of Marconi’s CQD continued for some extra years, especially by British operators, and the first distress call that came from Titanic was a CQD as well, when Captain Smith gave the order to call for help, the radio officer Jack Phillips initially sent out a CQD distress:
12.15 a.m., 15 April 1912, R.M.S. Titanic to Any Ship: “CQD Titanic 41.44 N 50.24 W”
to some minutes later include SOS as well
12.17 a.m., 15 April 1912, R.M.S. Titanic to Any Ship: “CQD CQD SOS Titanic Position 41.44 N 50.24 W. Require immediate assistance. Come at once. We struck an iceberg. Sinking”
where, ironically, the other radio officer, Harold Bride, jokingly suggested that it may be his last chance to use the new distress call.
Harold Bride was among the survivors, to publish his exclusive story Thrilling Story by Titanic’s Surviving Wireless Man and to testify in the American and British inquiries into the Titanic disaster, where a report from the American inquiries recorded a provided explanation of the meanings behind the two most popular distress codes: “The Attorney-General explained that the signal C.Q.D. meant ‘Come quick, danger’, and that this had now been substituted for S.O.S. ‘Save our souls’, followed by Harold’s rebuttal, who stated that the distress signal is not made out of the first letters of three words but is merely a code.
To later Marconi testify for the same, and the Marconi Yearbook of Wireless Telegraphy and Telephony from 1918 to clearly state out that: “This signal [SOS] was adopted simply on account of its easy radiation and its unmistakable character. There is no special signification in the letter themselves.”