Much about the Chinese sailors’ lives was influenced by the currents of history, including their presence on the Titanic to begin with. Labor strikes in Britain had left them without work, so their employer reassigned them to a North American route. The Titanic was supposed to take eight sailors as third-class passengers from Southampton, England, to their new ship in New York.

When the liner struck an iceberg late on April 14, the eight men acted quickly. Five made it into lifeboats, but the other three fell into the subzero water with hundreds of others as the ship was swallowed by the sea.

Two of those three sailors, Lee Ling and Len Lam, are believed to have died in the water. The third, Fang Lang, clung to a piece of debris and waited until a single lifeboat returned to search for survivors, making him among the last to be saved.

Credit…Photo Courtesy of the Fong Family

Fang’s rescue was the inspiration for the end of the movie “Titanic,” and was even portrayed in a deleted scene. (Mr. Cameron, an executive producer of “The Six,” is interviewed in the film.) But for decades after the sinking, the Chinese survivors were painted by the ship’s owner and the news media in a negative light, which may have been one reason their story remained unknown even to some of their descendants.

As the liner sank, four of the men reached a crowded, but not full, lifeboat that included J. Bruce Ismay, the Titanic’s owner, who was later criticized for not going down with his ship. Speaking to investigators after the disaster, Mr. Ismay described the Chinese men as stowaways. News reports also accused them of dressing as women so their rescue would be prioritized.

Though the filmmakers planned to report whatever they discovered, “it turns out we didn’t find any direct evidence of them doing things they were accused of and there was a much better explanation,” said Arthur Jones, the Shanghai-based director of the film.