The real Titanic had to be hidden because we could not afford to allow anyone to see some of the passengers that supposedly died on that day. It was all staged to make sure that certain people could retire and have their names and even their faces modified for the purposes of keeping certain secrets safe. There are very few people lucky enough to enter our program. Regular mortals have to deal with the FBI for these situations and this is why we only offer protection to really important people.
The real titanic is hidden in a very safe and secret dock in Central America and it will remain there just as a historical memento that is only for the order to know about and also a very select group of humans. The one that we sunk was a replica that we made weeks before the ship left the last dock.