Titanic footage (lost 1912 recordings; existence unconfirmed)
The RMS Titanic was, at the time of its building, the largest passenger ship. It was met with a tragic fate when it sunk on its maiden voyage on April 15, 1912. Over 1,500 people perished with only 700 survivors out of its 2,200 passenger count.
While still photographs of the Titanic are quite common, actual film footage of it is extraordinarily rare. For many decades, the only known surviving footage was of the ship being docked shortly after its construction. Then, in 1997, film director James Cameron sought out extra surviving footage, particularly that of the ship departing with its passengers waving to the distance. No footage was known to exist, with many historians thinking Cameron was crazy. Then, the following year, footage was uncovered of the exact clip Cameron was looking for, until historians confirmed the footage was of Titanic's older sister, the RMS Olympic departing.
It has been confirmed that many other clips were taken of the boat after its construction, though none of these have surfaced. One passenger was confirmed to have brought a film camera on board, which may have actually been saved from sinking with the ship. This has left many people longing to see possible film from the inside of the ship, but the footage has never been recovered. It has even been theorized that there may have been some footage taken of the ship's sinking from both inside and outside on a lifeboat (this claim has been heavily disputed as "incredibly unlikely", however).