Canadian director James Cameron has two passions - moviemaking and deep-sea diving.

His Chinese fans were in for a visual treat when a documentary movie recently screened on the mainland had the director of Titanic and Avatar undertake a challenge to dive to the world's deepest known pocket.

Deepsea Challenge 3D, shows Cameron diving around 11,000 meters into the Marianas Trench in the Pacific Ocean.

He piloted a submersible designed and made by his engineering team after a seven-year exploration and more than 10 test dives. He claimed the adventure realized a "lifelong" dream, according to Reuters.

"It's such an internal drive for him, that once he's started that train, it's not going to stop. This isn't an option for him. He has to do it," his wife Suzy Amis is shown as saying in the documentary.

"It's a true story, so it looks like a science-fiction movie," Cameron said in a video message to reporters in Beijing on Feb 10. He added that he didn't direct the documentary.

His team of documentary moviemakers and the National Geographic Society helped to get him into the Marianas Trench, he added.

"I hope Deepsea Challenge 3D inspires you as my expedition team inspired me," Cameron said.

Receiving an average score of around 8.5 out of 10 on mainstream movie review websites, such as Douban.com and Mtime.com, most viewers said that they liked the reality production.

"Cameron is really a god of filming. Even a documentary can look so dramatic and attractive in plot," wrote a Chinese fan on Mtime.com.

But some said the documentary would have to unfairly compete with blockbusters that have been released during the Chinese New Year holidays, considered the most profitable time at the box office.

"I waited for the movie for a long time. Media reports had said the earlier release date was supposed to be in August," says Xiang Jian, a 26-year-old fan from Hunan province. "Only a quarter of more than 120 cinemas in Beijing are screening it, and most play it at 10 pm and other non-prime showtime."

The Oscar-winning director was known to Chinese moviegoers as early as in 1995, when his action thriller True Lies became the first Hollywood blockbuster on the mainland.

His fame rose in 2012, when the fantasy epic Avatar stirred a frenzy in China, causing some fans to line up overnight to buy tickets.

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