The Earth’s oceans are vast and largely unexplored, covering over 70% of the planet’s surface. Despite our limited knowledge of the depths below, scientists have been able to determine both the average and maximum depths of the oceans through a variety of methods. Understanding these depths is crucial for a range of scientific and practical purposes, from predicting oceanic currents to exploring the mysteries of deep-sea life.

So, how deep is the ocean (on average) and the Mariana Trench, the deepest part of the world’s oceans? Here is the amazing video published by National Geographic below, answering this very question.

Seven miles is a long way down… more than a mile deeper than Mount Everest is up. To reach the deepest part of the Mariana Trench, James Cameron will descend past some pretty amazing milestones. Here’s a glimpse.

On March 26, 2012, Canadian film director James Cameron (born August 16, 1954) reached the bottom of the Mariana Trench in the submersible vessel Deepsea Challenger. He is the first person to do this on a solo descent and is only the third person to do so ever.

The first multi-person crewed descent was performed by using Swiss-designed, Italian-built, United States Navy-owned bathyscaphe Trieste which reached the bottom at 1:06 pm on 23 January 1960, with Don Walsh and Jacques Piccard on board. An iron shot was used for ballast, with gasoline for buoyancy.

The onboard systems indicated a depth of 11,521 meters (37,799 feet), but this was later revised to 10,916 meters (35,814 feet). There were also two uncrewed descents: ROVs Kaikō in 1996 and Nereus in 2009.

These first three expeditions directly measured very similar depths of 10,902 to 10,916 meters.

The average depth of the ocean

The average depth of the ocean is 14,000 feet (4,267 meters).

How deep is the ocean: important points

The video covers Cameron’s descent in one minute.

  • 0-660 feet (0-200 meters) 90% of ocean life lives here.
  • 800 feet (243 meters) Dive depth of the nuclear submarine.
  • 1,090 feet (see notes 1) Deepest recorded scuba dive.
  • 3,300 feet (~1,000 meters) Latest trickle of sunlight.
  • 9,816 feet (2,992 meters, see notes 2) Deepest diving whale (Cuvier’s Beaked Whale).
  • 12,467 feet (3,800 meters) Titanic‘s final resting place.
  • 14,000 feet (4267 meters) Average depth of the ocean.
  • 25,262 feet (7,700 meters) Snailfish, the deepest living fish ever filmed.
  • 29,029 feet (8,848 meters) Mount Everest, also known in Nepal as Sagarmāthā, and in Tibet as Chomolungma. Earth’s highest mountain. It is located in the Mahalangur mountain range in Nepal. Its peak is 8,848 meters above sea level.
  • 35,813.65 feet (10,916 meters) Depth Trieste reached with Don Walsh and Jacques Piccard on board.
  • 36,070 feet (10,994.136 meters) James Cameron reached in 2012 in the submersible vessel Deepsea Challenger.
  • 36,069.55 feet ± 131.234 feet (10,994 meters ± 40 meters) maximum-known depth of the Mariana Trench (see notes 3).
Ocean depth zones infographic, vector illustration labeled diagram
Discovering the Depths: A Visual Guide to the Layers of the Ocean. This image showcases the varying levels of the ocean, from the sunlit surface to the completely dark hadal zone, the deepest region of the ocean, lying within oceanic trenches. Each layer is home to unique ecosystems and geological features, with temperatures and pressures that challenge even the hardiest of creatures. The deepest point of the Earth’s oceans lies at 36,069.55 feet ± 131.234 feet (10,994 meters ± 40 meters). It is the maximum-known depth of the Mariana Trench (the Challenger Deep). Understanding these depths is crucial for mapping the ocean floor, monitoring climate change, and developing sustainable fishing practices. Image source: Deposit Photos
How deep is the ocean? Challenger deep
How deep is the ocean? The Challenger Deep is the deepest known point in the Earth’s oceans.


  1. The video says 1044 feet, but it was then. In 2014, Ahmed Gabr, a 41-year-old Egyptian diver broke the record with 1090 feet 4.5 inches (332.35 meters). Ahmed’s amazing dive broke the previous mark of 318.25 m (1,044 ft) by South African Nuno Gomes in 2005, also off the coast of Dahab.
  2. In the video, it is marked as 8200 feet, but in 2014, Cuvier’s Beaked Whale Sets Records for the Longest and Deepest Dive by reaching a depth of 2,992 meters (1.9 miles or 9816.27 feet).
  3. Some unrepeated measurements place the deepest portion at 11.03 kilometers (6.85 mi, 36187.664 feet).


M. Özgür Nevres
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