There is much mystery and misinformation surrounding the origin and use of maritime distress calls. Most of the general populace believes that "SOS" signifies "Save Our Ship." Casual students of radio history are aware that the use of "SOS" was preceded by "CQD." Why were these signals adopted? When were they used?

The practical use of wireless telegraphy was made possible by Guglielmo Marconi in the closing years of the 19th century. Until then, ships at sea out of visual range were very much isolated from shore and other ships. The wireless telegraphers used Morse Code to send messages. Morse Code is a way of "tapping" out letters using a series of dots (short signals) and dashes (long signals). Spoken, short signals are referred to as "dits" and long signals are referred to as "dahs".

By 1904 there were many trans-Atlantic British ships equipped with wireless communications. The wireless operators came from the ranks of railroad and postal telegraphers. In the same year the Marconi company suggested the use of "CQD" for a distress signal. Although generally accepted to mean, "Come Quick Danger," that is not the case. It is a general call, "CQ," followed by "D," meaning distress. A strict interpretation would be "All stations, Distress."

At the second Berlin Radiotelegraphic Conference 1906, the subject of a danger signal was again addressed. Considerable discussion ensued and finally SOS was adopted. The thinking was that three dots, three dashes and three dots could not be misinterpreted.  It was to be sent together as one string.

Source:   Courtesy of Neal McEwen  from an article entitled "SOS", "CQD" and the History of Maritime Distress Calls.

History of Maritime Distress Calls & Titanic Disaster
A partial log of the calls for help from the Titanic as noted by other ships
and land based stations.  The Titanic's radio log book went down with the ship .

12.17 a.m.
15 April 1912
R.M.S. Titanic to Any Ship:
"CQD CQD SOS Titanic Position 41.44 N  50.24 W. Require immediate assistance. Come at once. We struck an iceberg. Sinking".
12.20 a.m.
15 April 1912
R.M.S. Titanic to R.M.S. Carpathia:
"Come at once. We have struck a berg. It's a CQD, old man. Position 41.46 N  50.14 W"
12.25 a.m.
15 April 1912
R.M.S. Carpathia to R.M.S. Titanic:
"Shall I tell my captain? Do you require assistance?"
12.26 a.m.
15 April 1912
R.M.S. Titanic to R.M.S. Carpathia:
"Yes, come quick!"
12.32 a.m.
15 April 1912
R.M.S. Carpathia to R.M.S. Titanic:
"Putting about and heading for you".
12.40 a.m.
15 April 1912
R.M.S. Titanic to R.M.S. Carpathia:
"SOS Titanic sinking by the head. We are about all down. Sinking. . ."
12:50 a.m.
15 April 1912
Titanic calls CQD and says, "I require immediate assistance. Position 41.46 N. 50.14 W." Received by 'Celtic'.
1:30 a.m.
15 April 1912
Titanic tells 'Olympic', "We are putting passengers off in small boats." "Women and children in boats, can not last much longer".
1.35 a.m.
15 April 1912
'Olympic' asks Titanic what weather she had. Titanic replies, "Clear and calm".
15 April 1912
Sometime between 2.15 a.m. and 2.25 a.m.
R.M.S. Titanic to R.M.S. Carpathia:
"SOS SOS CQD CQD Titanic. We are sinking fast. Passengers are being put into boats. Titanic."
(This is believed to have been the final wireless message sent from the Titanic.)

Bride and Phillips left the wireless room after that message, after being urged to leave their post by Captain Smith. They made their way to the Boat-Deck and began trying to help the other men in the releasing of collapsible Lifeboat B. While neither of them immediately made it onto a lifeboat, both were rescued from the sea. Bride's feet were so severely frozen he could not walk. Phillips died of hypothermia on or near collapsible lifeboat B, his body was never recovered.

The Titanic's call sign was MGY, and of the most famous radio messages in history was the CQD SOS sent from the Titanic's radio room on the night of April 15,1912. Details about the Titanic's wireless installation is available at sites listed below.


Here is an audio simulation of the distress message sent in Morse code from the Titanic radio room by radio operators Jack Phillips and Harold Bride.  The original message was sent  at 12:17 AM (ship's time) on April 15, 1912.  This only a simulation. There are no known recordings of the original transmission.   This audio clip  is recorded in .swf (shock wave format) requiring a .swf player to listen.  You can obtain a free copy of the Adobe player here.


Partial view of the Titanic's radio room.
Re-Creation of the original menu.

"CQD CQD SOS Titanic Position 41.44 N  50.24 W. Require immediate assistance. Come at once. We struck an iceberg. Sinking"