Cameron plumbs new depths (no, not that Cameron...)

Hollywood director James Cameron achieves his dream with journey into the deepest ocean trench

James Cameron has taken viewers to alien planets by directing blockbuster films including Avatar, but yesterday he professed to have discovered another world here on Earth.

Cameron, who researched his film Titanic with a series of submersible dives to the shipwreck, completed the first solo dive to the deepest place in the planet's oceans. The voyage to Challenger Deep in the Pacific's Mariana Trench lasted three hours as he journeyed almost seven miles down, going deeper than Mount Everest is high. "It was absolutely the most remote, isolated place on the planet. I really feel like in one day I've been to another planet and come back," he said, adding it was "very lunar".

There were several disappointments, including the failure to find any terrifying creatures. "We'd all like to think there are giant squid and sea monsters down there," he said. "Sometimes the ocean gives you a gift, sometimes it doesn't." There were not even any fish, and the only living creatures were shrimp-like and less than an inch long. Cameron said: "The bottom was completely featureless. I had this idea that life would adapt to the deep, but I don't think we're seeing that."

This expedition was the culmination of seven years of planning. It was the first time the voyage has been attempted in 52 years and the first carried out alone. Cameron whooped for joy as he stepped out of the sub after resurfacing, celebrated with the crew and said: "We did it."

He added: "It's a heck of a ride, you're just screaming down and then you're screaming back up ... I was thinking, man, it's a long way down. When you go past Titanic, then you go past Bismarck, then you go past where the Mir subs can go, you're only two-thirds of the way there."

Cameron said he had fantasised about going to the depths of the ocean ever since he was a child. He has made more than 70 deep dives in submersibles.

The feat was carried out in a lime-green sub, Deepsea Challenger, a craft fitted with 3D cameras that could withstand the huge pressures of the ocean floor. The craft was launched 200 miles off Guam on Monday, local time.

It did not run entirely smoothly. The craft was struck by mechanical difficulty, forcing Cameron to return to the surface earlier than planned. It also meant he lost some of the samples he had taken at the bottom. He is planning three or four more dives in the next few weeks.

The first manned expedition to Challenger Deep was made in 1960 by US Navy lieutenant Don Walsh and Swiss engineer Jacques Piccard, but the sand kicked up from the ocean floor, meaning they had no visibility at all. Walsh, who is now in his eighties, was aboard Cameron's expedition ship.