This movie was filmed in Pittsburgh, PA. Many of the actors are from the local area.
There is a character called Ida Strauss in this movie. Ida was the wife of Isador Strauss, the founder of Macy's Department Stores. Ida was being loaded onto a lifeboat but refused to go when she learned her husband was not permitted. She famously quoted "As we have lived together, so we shall die together. Where you go, I go."
Sections of the deck of Titanic were constructed in a warehouse that had formerly been used as a soundstage just on the outskirts of downtown Pittsburgh. The feature film, "Love and Other Drugs" starring Anne Hathaway and Jake Gyllenhaal filmed in the same facility in 2010.
The "floating corpses" in the North Atlantic scenes were actually members of the art department crew. Dressed in full costume, between takes, they would push lifeboats, floating ice chunks (made of wax) and various floating debris back into place for the next take.
To double the scenes of the lifeboats in the North Atlantic, a closed down public pool was used. The bottom was painted black and a large black wall was constructed to block out the background. The former pool was called "Ligonier Beach" and it's actually located in the Laurel Mountains about 90 minutes east of Pittsburgh. At over 1.3 million gallons, Ligonier Beach was once the largest swimming pool in the United States. Large oil barrels were pushed in and out of the water by production assistants to create the slightly choppy water effect.