The first two explorers to reach the very bottom of the ocean—a point in the Mariana Trench 35,798 feet below the surface—were Don Walsh and Jacques Piccard. They traveled there in a submersible called Trieste. This was way back in 1960. Their feat landed them on the cover of LIFE magazine.

For the next 52 years, Walsh and Piccard were also the only explorers to reach the very bottom of the ocean. No one else even bothered the try.

Until some guy named James Cameron came along.

You know, James Cameron: the director of The Terminator, True Lies, Titanic, and Avatar, among other obscure movies. You might have heard of him. It turns out that Cameron has a hobby: deep-sea exploration. Inspired by his boyhood dreams of scouring the oceans for new forms of life, Cameron has increasingly spent his time over the last few decades developing new submersible technologies and leading cutting-edge missions to shipwrecks such as the Titanic and the Bismarck—then releasing 3D films documenting the experience.

His latest expedition tops them all. Seven years ago, Cameron assembled a crack team of engineers to build a revolutionary submersible that he had in part designed: a vertical, torpedo-like vehicle known as the Deepsea Challenger. The goal was to get a human being to the bottom of the Mariana Trench for the first time since Cameron was a 5-year-old. And that human being would be the director himself.

On March 26, 2012, Cameron accomplished his mission. In his new documentary Deepsea Challenge 3D, out August 8th and directed by John Bruno, we can finally see what that experience was like—the experience of climbing into a cramped sphere and plunging to a pitch-black depth where even the smallest malfunction might mean certain death. (The water pressure alone would turn a man into a “meat cloud” in a nanosecond, Cameron colorfully explains.) It’s a fascinating, gripping, and ultimately inspiring film.

The Daily Beast recently spoke to Cameron about why deep-sea exploration is so important, why some Americans have become so hostile to science, and what’s wrong with Hollywood these days. We also snuck in a few questions about his next big project: the three Avatar sequels, which will be released between 2016 and 2018.

Excerpts:

You’ve never been one to shy away from a challenge. So which was harder: sinking the Titanic all over again or climbing into a tiny sphere and traveling to the bottom of the Mariana Trench?

[Laughs] Well, actually, they were kind of similar problems in terms of the amount of time and engineering that it took to solve them. But I was working with a much, much smaller team on the expedition. And while I may have put a bunch of stunt guys in peril on Titanic, it was my ass in the sphere on the dive. So I would say that one was more difficult.

What was the most difficult moment on this project—and the most exciting?

For me the most difficult time was Andrew’s accident. [Ed: Cameron’s producing partner Andrew Wight and underwater cinematographer Mike deGruy died in helicopter crash in the middle of shooting.] Being with the families afterwards and questioning the whole issue of being an explorer. All of the things that Andrew stood for and Mike deGruy stood for and that I’ve always stood for. There are risks that you take because they are important—because exploration is important. But all of that came into question. I’d never had that happen before at such a deep level.

And the highlight for me was touching down at the bottom of the trench. That had been our goal for seven years. It was the fulfillment of a dream. I was proud that we had built this thing and it had worked. And here was the definitive proof of it.

How did it actually feel, in the moment, to hit the bottom of the ocean?

You’re kind of falling in limbo. You’re in this black void. And there’s something about making that contact at the bottom that’s so concrete and undeniable that... I guess it’s like summiting a mountain. An upside-down Mount Everest. [Laughs]

You mentioned risk. You risked your life—and spent a lot of time and money—trying to get to the bottom of the ocean. Why is this so important? Why should it matter to everyone—not just to an explorer like you?

Look, I’m personally very interested in the science. I love deep-ocean science. But I don’t expect everyone to be interested in that. I think the value of it for the average person is more symbolic. To remind people that we’re still in an age of exploration. People think that we’ve explored the Earth—that we’re done. “Let’s go to Mars. Let’s check out other planets.” But we’re not done here on Earth when we have this vast, unexplored territory under the ocean. Just the trenches alone, which are deeper than 6,000 meters and go all the way down to 11,000 meters, where I was... those trenches add up to an area larger than North America. That’s a continent—an entire continent that nobody’s looked at. I mean, literally. Other than myself and Don Walsh and Jacques Piccard back in 1960, no human beings have dived down there and looked with their own eyes. We spent billions and billions of dollars going into space, but we forget about the ocean, which is actually a big part of the planet’s life-support system. It just gets ignored. When Congress goes through the budget and rips everything out, of course the first thing to go is ocean research funding.

Why can’t institutions and governments do this anymore? Why did it take a private individual like you? And is that the future of exploration?

We’re seeing it in space with people like Elon Musk and Jeff Bezos, too. So, yeah. I think that governments are playing a defensive game right now. They’re not thinking in terms of the inspirational dividends of doing this type of exploration. They’re living from poll to poll, from news cycle to news cycle. They just don’t want to do anything wrong, and they certainly are not about to do bold things. So it is going to be up to the individuals. I do think it’s a new paradigm. Don’t look to the government to do anything serious with exploration. It’s just not happening. We don’t even have a manned U.S. space program anymore. We built an International Space Station but we don’t even have a way to get to it. It’s a ludicrous scenario.

And forget about Mars. The U.S. government will never go to Mars. I’m just going to put a stake in the ground and say it. We’d rather rest on our laurels. The political will is not there. That’s why I think a film like this that inspires people about the idea of exploration can do some good.

Exploration used to be such a big part of American life: manifest destiny, landing on the moon. What changed? Why has our culture has become so hostile to science?

That’s one of my big pet peeves with American culture specifically. We’re very happy to cherry-pick from science the things that we want and like—all of the new gizmos coming out of Silicon Valley. But out of the other side of our mouth, we’re saying that evolution hasn’t been proven and that climate change is a bunch of bunk. I’m sorry, but you can’t do that. You’ve got to either accept the fact that the tunnel diode in a semiconductor chip is explained by quantum mechanics—or it’s magic. You can’t do superstition and science in the same sentence.

You’ve said that we’re destroying our oceans faster than we’re understanding them. What did you mean by that?

We’ve killed off 90 percent of the apex predators—the big fish. We’ve basically eaten them. Everybody talks about sustainable fishing, but the very, very best that sustainable fishing could achieve is to try to maintain some portion of that remaining 10 percent. But nobody can prove that that’s sustainable. So over the long term, when you interrupt the ecosystem so much, it can’t recover. And now they’re doing these deep trawls that are destroying deep ecosystems before they’re even understood or visited or mapped. The thing about the ocean is that it’s not like the land. You can learn an awful lot about the land from sensors in a plane or a satellite. The ocean, you’ve got to get in there. You can only see from above about a meter below the surface. Look at the fact that a bunch of punks came along and built a vehicle that no institution or government in the world has. To me, that was part of what we were trying to show—that we’re really underfunded and underinstrumented right now.

You said you almost quit Hollywood before making Avatar. Why?

I felt there were a lot of ways that I could spend the stub end of my life cycle that were more productive. I don’t mean to put Hollywood down. I love Hollywood. I love filmmaking and all that. But we do tend to get a little wrapped up in our bubble of delusion, like it’s super-important. I think science and exploration and understanding the natural world are more important than that.

If some fan came up to you on the street and said “Stop mucking around with submarines and get back to making kickass movies,” what would you say to him?

[Laughs] I get that speech in fairly polite terms from 20th Century Fox once in awhile. [Laugh] No, I mean, they understand that I’ve got this dual life. For a while I do exploration, then I come back and do movies. And I’ve made a major decision in that regard by committing to the three Avatar sequels. That’s going to be five or six years of my life. So I’ve definitely doubled-down on the movie side. But not in a general sense—not like, “Hey, I’m open for business as a director.” I’m open to the Avatar movies.

Why just the Avatar movies?

Because I think Avatar is a really good blend of entertainment and substance. Of actual meaning that makes you think about our relationship with nature. It has a greater value than just entertainment.

Where are you in the Avatar process? You said in April that all three scripts would be finished by now.

Look, the question “How long does it take to write a script?” is like “How long is a piece of string?” It takes until it’s good. And it can’t just be good. It has to be great. So it’s a creative process. There’s myself and four other writers. And right now our sleeves are rolled up and we’re in that process. It might take another few weeks. It might take another few months. I don’t want to commit to a time right now because people ran away with this thing about six weeks like it was some sort of filing deadline for a story. It doesn’t work that way.

Meanwhile, we’re developing the hardware, we’re developing the software. That’s a full-time job for the team down in our Manhattan Beach studios. We’ve got a full art department team cranking here and in New Zealand developing every creature, every character, every environment. You know what it’s like. There was no location photography on Avatar. Every flower, every blade of grass, every tree had to be created in CG. And that’s really the bulk of the work. So as stories are coming into focus, elements are being created—every prop, every weapon, every bit of warpaint and makeup, every bit of hair. It all gets created in parallel. Everyone always asks me, “When are you going to start shooting?” But that’s a conventional movie question. It’s irrelevant on Avatar. The answer is that we’re in it 24/7 right now.

No sleep for James Cameron.

[Laughs] I do sleep. Sometimes.

A few hours here and there.

Right. [Laughs]

One critic said that too many of our great directors are stuck in franchise mode—that they’re cranking out sequels when they should be pursuing original stories. Was he wrong?

That’s a studio problem. I agree with that. I agree that the studios have sequel-itis. But that’s not my problem. I made a decision similar to what George Lucas did when he decided he was going to stay in the Star Wars universe for a long time. I feel that everything I need to say—stylistically, thematically, even in terms of designs I want to see—I can do in the Avatar universe as I’ve imagined it. So when that cycle’s done in five years, I’ll probably do something very different. And it might be more ocean exploration—in fact, it probably will be, because I will have been away from it for so long.