What is the Meaning of SOS? The Fascinating History of the Universal Distress Signal

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meaning of sos

What does SOS mean?

Are you wondering about the meaning of SOS? Contrary to popular belief, SOS does not stand for “save our souls” or “save our ship”, these are backronyms. In fact, the famous three letters in SOS stand for nothing.

SOS is a distress call in Morse code consisting of a continuous string of three dots, three dashes, and three dots, with no other meaning on its own. But, as three dots mean the letter “S”  and three dashes mean the letter “O”, then operators started calling this distress call “SOS” for convenience.

sos meaning
Morse Code apparatus and alphabet.

The three letters in SOS are easy to remember, making them a powerful visual signal for anyone in trouble. In fact, the three letters have become a separate and recognizable visual distress signal.

When someone needs help, they can spell out SOS on the ground, hoping to be seen by rescuers. What’s amazing is that SOS can be read even if it’s written backward or upside down, making it an incredibly effective way to call for help in an emergency.

But how did this random combination of dots and dashes become the universal distress signal we use today? 

To answer that, and to fully understand the SOS meaning, we need to go back to the early days of wireless telegraphy, before the invention of Morse code. At that time, people used different methods to communicate over long distances, such as flags and smoke signals. 

But with the invention of the telegraph, they could send messages through wires. And later with the development of wireless telegraphy in the late 1890s, they could send them through radio waves. 

This new technology brought a new challenge: how to ask for help in an emergency.

Listen to an SOS message in Morse Code

CQD Meaning

cqd meaning
Telegraph operator.

In 1904, there was no international standard for a distress signal. The Marconi telecommunication company, which played a significant role in developing wireless telegraphy, suggested using “CQD” as a distress signal. 

Many people think that CQD means “Come Quick, Danger” or “Come Quickly, Distress” but these are also backronyms. 

CQD is actually a combination of two signals: “CQ”  (“sécu“, from the French word sécurité)  which means “alert message to all stations”,  and “D” which Marconi added to indicate “distress”. 

CQD was used and interpreted by telegraph operators at the time as “All stations: Distress”. Marconi operators around the world began using CQD as the distress call prior to SOS, but it never became an international standard. The reason was CQD could easily be misunderstood with the general call CQ, especially if the signal reception was poor or interrupted.

Around the same time, the US Navy was proposing the use of the signal NC, which stands for “In distress; want immediate assistance”. This signal was easy to remember and recognize and had the advantage of being more specific to distress situations.

And in 1905, the German government implemented a new distress signal as part of their  telegraphy regulations. The signal was a Morse code repeated three times without a pause, followed by the station’s call sign. Countries did not adopt the German signal, and it was soon replaced by the now international SOS signal. 

The origin of SOS dates back to 1906, when the SOS signal was introduced during International Radiotelegraph Convention in Berlin. Attendees from various countries agreed to use the continuous signal of three dots, three dashes, and three dots as the international signal doe distress, starting in 1908. 

This signal was simple to remember and recognize, and it was unique, which made it easy to distinguish it from other signals.

Initial adoption of the SOS distress call

what does sos mean
Titanic used SOS to signal the sinking of the ship.

SOS was first used in an emergency on June 10 1909, when the SS Slavonia hit rocks near the coats of Azores islands (Portugal). Two ships that were in the area received the SOS call and assisted the SS Slavonia with the rescue. 

Two months later, on August 11, 1909, the steamship SS Arapahoe became adrift off the coast of North Carolina due to a broken propeller shaft. The ship sent out the SOS signal, which was picked up by nearby S.S. Iroquois and led to the successful rescue of the SS Arapahoe. 

But the most famous use of the distress signal came three years later when the Titanic used SOS to signal the sinking of the ship.

As you can see, SOS has an interesting history and is still a simple and reliable way to ask for help during emergencies. Knowing its meaning can be a life-saver, especially when you’re out on the water or exploring nature. 

Next time you’re out there, why not test your friends’ knowledge and ask them if they know the meaning of SOS? 

FAQ

When was SOS first used?

distress call prior to SOS

The first recorded use of SOS in an actual emergency was on June 10th 1909 when the liner SS Slavonia was wrecked off the Azores islands. On that day two nearby ships picked up her call and helped with her rescue. Two months later, on August 11, 1909, the steamship SS Arapahoe became adrift off the coast of North Carolina due to a broken propeller shaft. The ship sent out the SOS signal, which was picked up by nearby S.S. Iroquois and led to the successful rescue of the ship. But the most famous use of the distress signal came three years later when the Titanic used SOS to signal the sinking of the ship.

What is the difference between SOS and Mayday?

The Mayday distress signal is primarily used in voice communications, such as on a radio or over the telephone. It is derived from the French “m’aider” which means “help me,” and was introduced in 1923 and it is typically repeated three times to ensure that the message is clearly understood.
The SOS distress signal, on the other hand, is primarily used in Morse code transmissions and is recognized as a visual or audible signal. It consists of three dots, three dashes, and three dots, and it can be transmitted using any form of radio communication equipment.

Did Titanic use SOS or CQD?

Marconi radio operators on the Titanic initially used CQD and then SOS to call for help during its sinking.

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AUTHOR

Hi I am Peter, I absolutely love being out on the water and I have a deep passion for all things nautical. Sailing has been a huge part of my life and I plan to continue doing it for as long as I can. When I'm not out sailing, I enjoy spending time with my family and friends, reading a good book, and listening to music.