That might be true and all but the proper procedure isn't neccessarily standard practice. There's lots of black letter regs that aren't standard practice because they don't need to be and this is one of them. It's like yelling fire, people aren't going to ignore you cause you don't follow a rule that requires you to do it in certain intervals if it's serious. The crew messed up in a lot of ways that night but not doing everything they could to contact assistance isn't one of them. They used morse(and the supposed initial conversation that ended is a fascinating topic), they used rockets, they used wireless. They even used both the old(CQD) and new code(SOS) just in case people weren't using the new one yet(probably the most competent thing the Captain did after the sinking was directing the wireless operators to do that). If the rockets indeed scared away a third ship which I think is what likely happened, it's not like the absence of rockets would have meant they'd have neccessarily came to help.According to this, Titanic should have fired rockets at 1 minute intervals to signal distress She didn't.
When Is A Rocket Called A Distress Signal Or Just A Flash In The Sky? - Titanic Historical Society
According to information entered into the record at the British Enquiry, the Titanic carried thirty-six socket signals. The White Star Line provided these thirty-six signals to be used in case of emergency, and they were the latest pyrotechnics for maritime use. What made them different from previous illuminations was they carried an explosive device or report [a loud sound in addition to illumination] in the nose of the rocket and also sent a shower of white stars cascading down as the “socket signal” exploded several hundred feet above the ship firing them.
The 1912 International Rules of the Road governing Signals of Distress are quite clear: Article 31: Class 1, called for – a cannon or explosive device [with report] fired at one minute intervals. The device’s report was the sound of distress.
Article 31: Class 3, covered the sight of distress which is a rocket of any color fired one at a time at short intervals.
For the Titanic to fire distress signals using the rockets supplied her, the crew should have fired its socket signals at one minute intervals. It was that simple. By doing so, the rockets would be international “signals of distress.” An explosion or report at one minute intervals satisfies the sound signal requirement and the white shower of stars at one minute intervals satisfies the sight requirement. If this procedure had been followed, no one could ever question the meaning of the Titanic’s rockets