It is believed that British ocean line Titanic was the first ship to send the SOS. But it is not so. The first SOS message was sent by the American steamer Azaohoe in August 1909 when it was disabled due to a broken propeller shaft. Though SOS stands for ‘Save Our Souls’, the letter SOS was chosen simply because the Morse Code for them (three dots, three dashes, three dots) was easy to remember and transmit.
Before the SOS was used as a distress call, the CQD was in wide use. The first ship to send out a CQD was the White Star Liner Republic, which sank due to collision with the liner Florida off Nantucket on January 23, 1909. The Republic’s English radio operator, Jack Binns, became an international hero for sending out, with emergency power, this first ship-radio distress call.