What does SOS stand for?
SOS does not stand for anything. It was chosen as an international distress signal in 1906 because its Morse code, three dots, three dashes, three dots, is simple and easy to recognize.
In Morse code, S is three dots and O is three dashes, so SOS is sent as one continuous signal: ··· − − − ···. It is easy to send and hard to mistake, even in poor conditions. It was adopted at the International Radiotelegraph Convention in Berlin in 1906 and became effective in 1908.
Popular backronyms, phrases invented later, include save our souls and save our ship, but these were not the original meaning. Before SOS, ships used other signals, such as CQD. The Titanic sent both CQD and SOS when it sank in 1912, helping make SOS widely known.
Modern distress signals
Today, ships and aircraft mostly use satellite-based distress systems. In voice radio, the distress call is Mayday, from the French m'aidez, meaning help me. SOS is still recognized worldwide and can be signaled with lights, sounds or even written in the sand.
Did You Know?
Many smartphones now include an emergency SOS feature that calls emergency services and shares your location when activated.