Self-proclaimed "King of the world" and Oscar-winning 'Titanic' director James Cameron returns to the doomed cruise liner in 3D documentary 'Ghosts of the Abyss'.

Getting up close and personal with the 'legend' himself, I wondered that given that he'd made 'The Abyss' and 'Titanic' if this was the logical conclusion of all that's gone before? "I'm not sure it's the conclusion because I really enjoy the oceanographic subjects and I'm actually making another film that's on an oceanographic theme [exploring the wreck of the Bismarck]. But it's probably the conclusion of the Titanic exploration. I love this stuff, I love the idea of using filmmaking as an entree into the world of real oceanography and real exploration. It's really getting to live out a boyhood fantasy."

What drew you to the SS Titanic? "Two major influences. When I was a kid in the 60s, Jacques Cousteau burst onto the television scene with his specials. That was such a fantasy world to me that I really felt somehow called to learn to scuba dive and to want to do that type of exploration for myself. At the same time, I was reading a tremendous amount of science fiction. I related to that type of oceanographic exploration as very much like space travel, and I was fascinated by space travel. That was the sort of exploration I knew I couldn't really do, but the underwater stuff - there's no reason why I couldn't. So, I pursued that and whenever I wasn't off making a film over the last 20 years, I was off diving. They're equal passions, and getting to do film and use the film to pay for deep ocean research and exploration has been the culmination, bringing the two paths together. The audience at large is not really aware of that, so for them it seems kind of strange and quirky that a filmmaker should be doing this sort of thing, but it makes total sense from where I'm standing."

You must be in a chicken and egg situation with the technology! "Exactly. Every time you develop something you push a little further. The trick is to not be too premature in wanting to push to the next level. You can't do the film until you have the technology perfected. We'd actually worked out the 3D camera for another film, which was going to be a fictional film about a Mars mission."

What was your first visit to the wreck like? "Well, it was very different to what I expected. What I expected to have happen was what I show in the film, which is you approach it and it appears out of the darkness and it's all sort of grand and mysterious. In fact, what happened on the first dive was that we wound up practically running into it, taking evasive action and inadvertently landing up on the deck before I'd even had a chance to react to it. There were strong currents that day, the Russians hadn't dived the ship for about six or seven years, and quite frankly everybody was a little bit rusty. It was a very bizarre experience and not at all what you'd expect. In fact, it was several hours later that I was able to just stop and have that moment where the awe and mystery of the place hit me. After that I made myself a promise that on every dive I would take the moment to appreciate where I was."

Overall, did you enjoy making a documentary instead of a film? "Things never work out the way you expect them to, which is what's fun and interesting about doing a documentary. I think the two most interesting scenes in this film were the two scenes where we were having the worst time. Once when we had a storm hit us and we almost couldn't get the submersibles recovered; and the other time when we lost one of our $1 million robots and risked the second one to try to get it back. It was the unexpected things that turned out to be the most interesting. Documentary making is wild and unpredictable, and that's what makes it interesting."

And then there were the events of 11th September, 2001! "It was a strange and surreal experience to be at that site when September 11th happened, because I think there are some very strong parallels. Even though the reasons for the two tragedies are obviously very different, the impact of them on the populace of their times was actually very similar. These icons of their respective stages of civilisation destroyed utterly, just taken away, vanishing, almost impossibly."