Filmmaker James Cameron has become the first human to dive alone to the deepest part of the ocean - the 6.8-mile-deep Mariana Trench in the Pacific Ocean.

Abyss, The (1989) and Titanic (1997) filmmaker reached a depth of 35,756 feet (10,898 metres) in a specially designed 12-tonne submarine near Papua New Guinea, his mission partner, National Geographic, said.

Cameron's first words on reaching the bottom of the trench were "All systems OK".

He then tweeted: "Just arrived at the ocean's deepest pt. Hitting bottom never felt so good. Can't wait to share what I'm seeing w/ you."

Humans have only made it to the bottom of the trench once before - in 1960 when a two-man US Navy team spent 20 minutes on the seabed. Cameron is the first to do it solo.

The 57-year-old Oscar-winning director spent several hours collecting samples and taking video and photographs including 3D images that could help scientists better understand the unexplored part of Earth.

"Jim Cameron has surfaced! Congrats to him on his historic solo dive to the ocean's deepest point," said a Twitter message from Deep Sea Challenge, which organised the dive.

The Mariana Trench is a crescent-shaped scar in the Earth's crust which is more than 1,500 miles (2,550km) long and 43 miles (69km) wide on average.

Because of its extreme depth, it is cloaked in perpetual darkness and the temperature is just a few degrees above freezing, according to members of the mission team.

Source: Press Release