(CBS News) The Hollywood director who brought the world "Titanic" and "The Abyss" is learning about the ocean in a whole new way.

In a daring expedition, James Cameron traveled to the deepest part of the sea Sunday night where only two other humans have been.

"There had to be a moment where I just stopped and just took it in and said 'This is where I am, I'm at the bottom of the ocean, the deepest place in the world and what does that mean?

"I just sat there looking out the window, looking out at this kind of barren, desolate, lunar plain," Cameron said.

Cameron descended more than 35,000 feet underwater, nearly seven miles below the surface. He marked his arrival on Twitter, writing, "Just arrived at the ocean's deepest pt. Hitting bottom never felt so good."

Cameron was alone in a 25-foot tall torpedo-shaped submarine called the Deepsea Challenger, which took him to the bottom of the Mariana Trench, the lowest part of the ocean floor.

The trench is located in the middle of the Pacific Ocean about 200 miles southwest of the island of Guam. The trench covers a huge area, 120 times larger than the Grand Canyon and nearly two miles deeper than Mount Everest is tall.

Cameron is the first person to complete this dive alone. Two other explorers who reached the spot in 1960 are the only other humans to do so. It is a dangerous mission. The pressure at that depth is equivalent to three SUVs sitting on your toe. If the capsule were to leak, it would explode instantly.

Read more at CBSNews.com, and at National Geographic's Deep Sea Challenge website.

Photo above: The explorer-filmmaker emerges from his sub after returning from Challenger Deep. Photograph by Mark Thiessen, National Geographic