All of the above. The deleted scenes are also fun to watch.
I wish they would have left this scene in the movie, however. Ignoring the story of the
Californian (the ship that was arguably closest to the Titanic in her time of need but remained still all night) and the "mystery ship" (a third ship seen by both steamers) were some of the most important historical information omitted from the movie, but so I can only assume that James Cameron must not have an opinion on this lingering mystery of the Titanic lore. "A Night to Remember," the 1958 British movie, does include a scene where this "light on the horizon" is shown.