A Chinese expedition to the deepest waters on Earth has reached the incredible depth of 35,791 feet.

The Chinese submersible Fendouzhe is on an extended mission to map the depths of the Mariana Trench, a region in the western Pacific Ocean that is thought to contain the deepest ocean trenches on the planet.

Only 13 people have visited the forbidding region before. The Fendouzhe has made multiple dives in recent days.

In November, it set a national record for manned deep-sea diving after setting down in the deepest known point of the trench, Challenger Deep.

Fendouzhe was launched from the scientific vessel Tansuo-1

On November 10 Fendouzhe transmitted the world's first live video from Challenger Deep.

The incredible pressure at such depths makes survival a risky affair and only a very few craft have ever ventured into the trench’s murky waters.

Part of the motive behind the Chinese mission is to investigate the feasibility of mining rare and exotic minerals at those depths.

The trench is deeper than Mount Everest is high

The water pressure at the bottom of the trench is around 8 tons per square inch, around a thousand times the atmospheric pressure at sea level.

"It takes more than two trials before we can call it a real success," Zhu Min, a researcher at the Chinese Academy of Sciences involved in the mission, told Chinese state television channel CCTV.

Chinese Academy of Sciences' 6,250-ton submersible support ship Tansuo 1 (meaning: to explore) made her first voyage to the region in 2016

Victor Vescovo’s Deep-Submergence Vehicle DSV Limiting Factor holds the absolute depth record, at 35,850 ft, which was established in April 2019.

Amazingly, there are animals living at those impossible depths. 60 years ago, the submersible Trieste made the first descent into the Challenger Deep and one of the crew described "some type of flatfish" lying on the seabed that they described as “a monster of steel.”

Since the Trieste in 1960, only a few crewed missions have gone so deep. Titanic director James Cameron made a solo descent in 2012, and described finding a "desolate" and "alien" environment.