Science and exploration "are the two things that I'm more excited about in the world," according to "Titanic" director James Cameron. "I do those movies to get a little money so I can go do exploration. That's the fun stuff."

The filmmaker brought his Deepsea Challenger submersible to the District on Tuesday, parking what he described as his "Kawasaki racing green sub" on the Senate side of Capitol Hill and then on Pennsylvania Avenue about two blocks from the White House.

"I'm gonna go make two more 'Avatar' movies, so I'm going to be busy for the next few years," Cameron said of his decision to donate the sub to the Woods Hole Oceanographic Institution. On his way from California to deliver it to Massachusetts, he's making educational stops to pitch deep sea exploration.

"How is it that we've managed to get into the 21st century thinking that we've explored this whole planet, and we've missed an entire continent," he said. "The idea behind building this thing was to open that up."

Cameron, who says he has "always had an affinity for the ocean," commissioned the manned (or "personed," as Cameron pointedly noted, in deference to the many female oceanographers) submersible, which took seven years to build, and piloted it more than 35,000 feet below the ocean's surface.

"Sending a piloted vehicle down gets a lot more media and public attention," Cameron said at a Capitol Hill briefing. "I don't have a degree in any of the sciences or in engineering, but I didn't have a degree in filmmaking either, and that didn't stop me."

He told congressional staff members that he does not have a "specific call to action" on policy, but that it "boils down to funding" deep sea exploration. He and Dr. Susan Avery, director of Woods Hole, compared exploring the deeper ocean to exploring space -- but said the former has been neglected in comparison.

"As much as I love space exploration in the abstract, going to Mars is not speaking directly to our life-support systems," Cameron said. His first two speaking appearances were a warm-up for his appearance at the Senate Commerce, Science and Transportation Committee in the afternoon, where he made a similar pitch to some of the lawmakers holding the federal purse strings.