For comparison, most ocean life lives above a depth of 660 feet. Nuclear submarines hover around 850 feet below the surface as they travel through the ocean waters. The Mariana Trench is a crescent-shaped dent in the floor of the Pacific Ocean, extending over 1500 miles long with an average width around 43 miles and a depth of almost 7 miles (or just under 36,201 feet). Something unusual about these sharks is that they have joints in their jaws which allow them to actually move their mouth forward … They sense their prey using eletro-perception and smell and need to wait until they are close to their prey before attacking, as these sharks are fairly slow. These sharks have only been observed a handful of time by humans. Also in the Mariana Trench lives the Goblin Shark. In the abyssal zone light does not reach, therefore the entire trench is in complete darkness. Also, the deeper you go in the ocean the colder it gets. I'm sure you can imagine how cold it gets, around 34 degrees Fahrenheit (1 C). However the array of animals do have bioluminescent genes. The Mariana Trench stretches in a horseshoe-like shape around 2,550 kilometers (1,580 miles) in the eastern Pacific, with an average width of around 69 kilometers (43 miles) wide.