On January 7, 1904, the Marconi Company announced a new international standard distress signal to be used on all land and sea-based radiotelegraphs: CQD. While today, the signal recognized around the world to request assistance is SOS, back in 1904, when the idea of sending a distress signal from a ship was brand new, the company that ran most receiving stations had to come up with a signal that wouldn’t be mistaken for something less serious. CQ had already become known as a general alert, meant to rouse the attention of the operator so he could listen into a coming message intended for all stations. To indicate that this was a matter of grave importance and distress, the Marconi Company added the letter “D” for distress to the end of the normal CQ qualifier.
CQD didn’t last long, in part because of its own inadequacies, but also because a better system came along. The first problem was that it was broadcast as a set of letters rather than a single code. There was the possibility that with a poor signal the third letter would drop off and recipients would miss the urgency of the broadcast and think it just another general alert. The Marconi Company rightfully took these alerts very seriously, threatening any operators who used them without a true emergency to warrant it with immediate termination. Ultimately, it was the introduction of a new standard at almost exactly the same time that edged CQD out of the picture.
SOS was the creation of the Germans. The letters themselves don’t actually stand for anything, but were chosen because of the morse code patterns they translate to: a simple, straightforward “. . . - - - . . .” The Germans opted to transmit them without spaces between the letters, allowing for endless repetition and making it less likely to be misunderstood in the event of weak signal. The issue came to an inflection point at the International Radiotelegraphic Convention of 1906 in Berlin, where it was decided that all ships and receivers would acknowledge SOS as a signal of distress and respond accordingly. It’s a good thing, too, because with the way that SOS has become a part of pop culture and general consciousness, it’s a blessing that we ended up with something catchier and more memorable than CDQ.