Cameron will be in a submersible about 5,200 feet from the surface of the world's oldest and largest lake — "unless it's bad weather, in which case I'll be getting drunk with the Russian crew in the port."

A longtime ocean enthusiast, Cameron has other underwater projects in the works. He says he is building a submarine in Australia that will take him 36,000 feet underwater - twice as deep as anyone has gone before. He is also developing an upgraded 3-D underwater camera and has plans for an underwater feature film that he said he might make before taking on an "Avatar" sequel.