SOS is the Morse code letters of the international call for help.   

The SOS signal was first adopted by the German government in 1905.  It was to be repeated by a ship in distress.  The following year it was established as an international call for help.

SOS was a continuous sequence of 3 dots, 3 dashes and 3 dots, or ". . . — — — . . .".  In Morse code 3 dots comprise the letter S, and 3 dashes comprise the letter O, so the call for help soon became known as "SOS". 

The letters "SOS" do not refer to any words.  The sequence was chosen because ". . . — — — . . ." is easy to transmit quickly and easy to recognize. 

But SOS soon became associated with phrases such as "Save Our Ship", "Save Our Souls", "Survivors On Ship", "Save Our Sailors", "Stop Other Signals", "Sink Or Swim" and "Send Out Sailors". 

SOS has also been used as a visual call for help made by 3 short, 3 long, and 3 short flashes of light.  SOS can also be spelled out using rocks or logs or written in snow or sand.

SOS is easily recognized upside down and backwards!

Refresh this page to hear the SOS signal again!