SOS has been internationally known since 1906. SOS was used mainly for ships as an emergency signal in the early days of radio communications. They were used when ships were in an emergency and this was the only way to accurately ask for assistance. Furthermore, SOS was also signaled by using lights. The SOS signal was first adopted by the German government. The Titanic was the first ship which used SOS signal. SOS was another wireless way of communication which titanic had used. Above is the picture of the message that was sent from the captain of the ship.