It’s going to be at least three years until the first sequel to the biggest box office film of all-time hits theaters, yet James Cameron is already teasing how a potential fourth Avatar film could serve as a franchise prequel. As for the sure-fire Avatar 2 & 3 – which will shoot together – Cameron is preparing to isolate himself to begin penning the interconnected screenplays, a task that may prove to be his most challenging writing endeavor to date.

When Avatar released to box office magic over two years ago, Cameron wasn’t shy about revealing that the sequel(s) would showcase the oceans of Pandora. Knowing Cameron’s affinity for underwater environments – as emphasized in his resume of film and documentary work – it came as no surprise, but now we have a better idea of what we means by exploring the moon’s aquatic setting.

Cameron appeared at the Best Buy New York launch event for the Titanic Blu-ray release last night where Coming Soon asked about his ideas and plans for going underwater in the sequel(s), considering what’s been covered in films like The Abyss and Titanic, and his documentaries: Aliens of the Deep, Ghosts of the Abyss, and Expedition: Bismarck.

“We’re doing ‘Avatar’ films now, so we’re making up an ocean ecosystem for Pandora. That’s gonna have less to do with the deep exploration that I’ve done than it has to do with my concerns about conservation of Earth’s oceans. The fact that we’re basically overfishing, climate change… a few degrees of temperature rise are gonna basically take out the coral reefs. All those beautiful images of the coral environments we all grew up with won’t exist in 50 years at the rate we’re going in terms of pumping greenhouse gases into the environment. These are the things that concern me.”

“I hope that explains it, ’cause people have connected the dots directly together. ‘Oh, going to the challenger deep has a direct connection to what we’re going to see in Avatar 2,’ and that’s not the case at all. It’s all the scuba diving I did before I even started the deep ocean stuff that has more of a direct connection to Avatar 2 & 3, which by the way won’t take place completely in or under the water. That’s just part of the environment of Pandora that we’re going to see.”

Cameron already explained that much of the familar locales presented in Avatar 1 will of course be back in the sequel, but by delving deep into Pandora’s oceans to bring attention to what he sees as nature-destroying industrialism in that type of environment, the creative and production teams are taking no shortcuts and will have to craft entirely new types plant life and sea creatures to go along with a technically more challenging shooting process.

In fact, it’s that challenging process and Cameron’s desire to again innovate on the technological side of filmmaking that’s pushing Avatar 2 further back than Twentieth Century Fox would like. Cameron mainstreamed 3D by developing new 3D motion capture process for Avatar and for the sequels, he aims to utilize underwater 3D motion capture which at this time, simply doesn’t exist yet. They’re also building a deep-sea vessel to shoot underwater sequences so we can see why a 2014 release for Avatar 2 simply isn’t feasible.

Shooting the films is one monumental challenge of its own, creating a story arc spread over several films, with each chapter having its own standalone story is another. In chatting with Hero Complex, Cameron touched on the challenging of developing the sequel screenplays and references The Matrix trilogy as an example he doesn’t want to follow.

“It’s a little bit of a daunting writing task because it’s two scripts and they’ve both gotta be done at the same time… I’m writing it as separate stories that have an overall arc inclusive of the first film. I don’t want to suffer from the ‘Matrix 2′ problem, where it just ends, like, what the hell? It’s gotta end. There’s gotta be a sense of conclusion, but also a sense that the journey will continue, and that’s a fine line.”

The story wasn’t the selling point of Avatar and the visual spectacle was often criticized as being a retelling of Dances with Wolves, but no one can discredit imagination and detail put into designing the ecosystem and wildlife that form the dangerous yet beautiful Pandoran paradise. Let’s hope that aspect carries over to the sequels while we get something more original from the story.

Follow Rob on Twitter @rob_keyes.

Sources: Coming Soon, Hero Complex