<P> Coordinates: 11 ° 21 ′ N 142 ° 12 ′ E ﻿ / ﻿ 11.350 ° N 142.200 ° E ﻿ / 11.350; 142.200 </P> <P> The Mariana Trench or Marianas Trench, located in the western Pacific Ocean approximately 200 kilometres (124 mi) east of the Mariana Islands, is the deepest point in the world's oceans . It is a crescent - shaped trough in the Earth's crust averaging about 2,550 km (1,580 mi) long and 69 km (43 mi) wide . The maximum - known depth is 10,994 metres (36,070 ft) (± 40 metres (130 ft)) at the southern end of a small slot - shaped valley in its floor known as the Challenger Deep . However, some, unrepeated, measurements place the deepest portion at 11,034 metres (36,201 ft). For comparison: if Mount Everest were dropped into the trench at this point, its peak would still be over 2 kilometres (1.2 mi) underwater . </P>

Who has been to the bottom of the marianas trench