The ship of theseus was actually a spaceship used by the precursors to reach earth. It was broken down into components which were then reused in human ships both to hide the truth and as part of a secret seafaring cult ritual.
The piece on the titanic accidentally activated during its maiden voyage and attempted to take the ship to the precursor base in Altantis, but since Atlantis was sunk, it took the ship under and crashed into the seafloor.
It was later recovered by the us military in a covert operation disguised as a civilian project and was a key component in winning the space race.