In the documentary of his record-breaking deep-sea dive, “Deepsea Challenge 3D,” James Cameron asks, “Am I a filmmaker who does exploration work on the side, or am I an explorer who does filming on the side?” It’s now been five years since Cameron’s last feature film Avatar, and in that time, the priorities of the most bankable director in Hollywood have sometimes been as murky as the deep sea. He has spent those years producing a fleet of documentaries about ocean exploration and deep-water life forms. His biggest project hasn’t been a mega blockbuster but building a deep-diving sub and piloting it more than 35,000 feet down into the Challenger Deep, the deepest part of the Mariana Trench.
