At the time, the Titanic was a great achievement in engineering, etc... but, ummm, it sank. It really wasn't the best ship for sea travel.
1,496 people died in the sea the night Titanic sank.
No ship was bigger when Titanic took to the sea - but the size she had been, at the time of the sinking, was surpassed by Der Imperator.
The Atlantic sea bed
A submarine best fits the description.
The Titanic was a sea for five days. The ship hit the iceberg on the fourth day and finally sunk, killing almost everyone that was onboard.
The main thing was for any commercial ship to carry enough lifeboats for all passengers and crew.
The Titanic is rusting and, after a few decades, the ship will be nothing but an orange spot of debris on the sea floor.
The Titanic was a ship.
That EVERY ocean liner had to have enough lifeboats for everyone on board and there had to be a 24/7 wireless on every ship.
A submarine is a ship that can travel underwater.
She was RMS Titanic - which stood for Royal Mail Ship. But she only took on that status when she loaded the mail. Until that moment she was SS Titanic (steam ship) like during sea trials, for example.
cherbourg France