The Titanic used CQD as well as SOS.
It was, however, sent on a Spark Transmitter.
Here's the original transmission.
http://www.geocities.com/CapeCanaver...72/titanic.wav
RRR = Surface Raider
In the early morning of January 23rd, 1909, whilst sailing into New York from Liverpool,
RMS Republic collided with the Italian liner SS Florida in fog off the island
of Nantucket.
This was the first occasion on which the CQD distress call had been sent by wireless transmission.
The first ship to transmit an SOS distress call appears to have been
the Cunard liner
Slavonia on June 10th, 1909,
according to "Notable Achievements of Wireless" in the September, 1910
Modern Electrics.