Maurice Evans., age 9, of St. Paul, Minnesota for his question.

Why is S.O.S. used as a distress signal ?

In 1912, the International Radiotelegraph Convention chose a radio signal to be used in emergency calls for help. The message was a short ones easy to send and noticeable enough to attract the attention of listening radio men.

The signaler simply sends out three short taps, or dots three longer taps, or dashes, and three more short dots. The message is repeated again and again. In Morse code’s three short taps are the letter S, three long taps are the letter 0, To the experienced radio man the dreaded three dots three dashes and three dots read: S. 0. S.  The letters themselves do not stand for any words.