110 years and one month ago the German government adopted the Morse symbol ...---... as the distress call for ships at sea. The code represents the letters SOS but without gaps between the letters.
and often remembered by the mnemonic Save Our Souls. The sequence was not selected for that reason, however but for its ease of recognition: It is the only symbol in Morse with more than eight key presses. Although gaining international ratification the following year there was some resistance amongst Marconi operators to its use. When the Titanic was sinking their Marconi operator intermixed SOS and CQD signals. CQ had been in use on land to indicate an alert or precautionary message and originated in the French word Securite. Marconi adapted this for use at sea by adding D for distress to the symbol in 1904 but it never gained international recognition outside the Marconi operators. It is believed that the first use of SOS by a ship in distress was the Cunard liner Slavonia in 1910 The correct way to represent the distress symbol is SOS as it is a continuous transmission of nine characters and not the three letters which it resembles. The sequence ...---... could also be represented in Morse as VTB, IJS, VGI, or SMB but SOS seems to have stuck.
With the advent of audio radio communications there was a need for a spoken distress term and in 1927 MAYDAY ( from the French m'aide - help me) was adopted.
Today is MayDay - 1.5.15