SOS was adopted as the International distress signal on 1st July 1908.
The Morse code signal is a sequence of three dots, three dashes and three dots. It was first adopted by Germany on 1st April 1905 and under the International Radiotelegraphic Convention (signed on 3rd November 1906), it was decided to be adopted as an international distress signal.
SOS remained the maritime radio distress signal till 1999, though it is still recognised as a visual distress signal.
