Building Just One Side Of Titanic Meant James Cameron Had To Use Some Mirror Image Trickery

James Cameron's romantic, tragic masterpiece "Titanic" hit theaters 25 years ago, but aspects of the film's production still manage to amaze viewers today. To bring the story of the doomed RMS Titanic to life, Cameron reportedly spent $40 million (per MovieWeb) building a massive replica of the boat, which is more than five times the price tag on the real ship that set sail for just one voyage in 1912.

While stories from behind the scenes of "Titanic" abound, the making of the epic seems to have been so jam-packed with creative filmmaking techniques that some of the most impressive details of the production are all but forgotten these days. For instance: did you know the "Titanic" crew actually built just half of the boat to scale in order to cut costs? It's a clever decision, but one that resulted in some trippy problems when it came time to film the scene in which Rose (Kate Winslet), her mother (Frances Fisher), and other characters board the ship at the Southampton dock.

In virtual press kit footage from Paramount Pictures, James Cameron, Kate Winslet, and producer Jon Landau spoke about the solution the director found when their half of the ship didn't end up matching famous images of the Titanic from history. "We made the decision to build only one side of the ship towards the ocean side of the tank into the prevailing winds," Landau explained. "And in doing so, we ended up building the starboard side of the ship. It forced us to locate Southampton dock on that side to shoot the whole sequence, but in fact, in history, it was on the port side."

Cameron says that the team "saved millions" by building just the starboard half of the Titanic, but that meant when it came time to shoot the big send-off scene, he had to come up with a plan to mirror the shot. "If I have a scene that takes place on the port side but I only have the starboard hull, then I have to shoot the scene on the starboard side and then turn the film around mirror-image later," Cameron explains. "It gave us a little bit of a brain teaser trying to figure out exactly how to cheat this thing so it would look right."

With a laugh, Cameron describes trying to keep the continuity of shots correct while reversing them. Presumably, some shots in the scene could be done normally, while anything that featured the ship itself had to be flipped. "'Where were you standing again? Who was on your right?'" Cameron recalls himself saying, adding that he had to make actors turn their hats around and hold the opposite hand than they did in previous shots. "It was a nightmare," he says in summation.

While the concept of "flopping" or mirroring shots is hard to conceptualize, it's a bit like when ambulances have the word "Ambulance" written on them in reverse so they'll be easily readable in your rearview mirror. In this case, all the elements of shots featuring the Titanic at Southampton port had to be reversed, so that when viewers saw the scene, it would look true to the photographs snapped of the Titanic before it sunk, like those shared by Smithsonian Magazine. It's a complicated process that star Kate Winslet freely admitted she didn't understand.

"This flopping thing, I just haven't been able to get my head around at all," Winslet said in the interview for Paramount Pictures' press materials. "One minute my parting's on this side, the next minute, no, we're flopped, it's on that side." Winslet said she found herself laughing when she'd "see men with 'White Star Line' written across their hats, just backwards." In the behind-the-scenes video, the backward lettering emblazons not just uniforms but also buildings. "I couldn't quite get my head around it so I just sort of gave up," Winslet concludes.

"Titanic" is an example of movie magic at its finest, and as the 4k, high frame rate 25th-anniversary rerelease approaches, surely even more stories from the set of the box office smash will be uncovered. In the meantime, I'll be searching eBay for a piece of movie merch I didn't know I needed until now: one of those extras' jackets that says "ENIL RATS ETIHW."

The 25th-anniversary re-release of "Titanic" hits theaters on February 10, 2023.