Thought-Provoking Facts About Ocean

The ocean is one of the biggest mysteries of mankind. People search out facts about the ocean for many reasons. Some are students looking for answers. Some seek to learn more out of pure curiosity. Others may be looking to impress friends or family. Whatever your motivation we have created this list of interesting facts about the ocean to document some of the more captivating facts about the largest bodies of water on planet earth.


  1. Earth is mostly water. Three-quarters of this planet is covered by water bodies, with the biggests ones being the five oceans (the Atlantic, Pacific, Southern, Indian, and Arctic oceans).
  2. Ninety four percent of all life forms on Earth are aquatic. From this number, ninety percent resides in the ocean’s “abyssal zone.”
  3. Humans have documented space and other planets better than they have mapped the ocean floor. It is estimated that only about five percent of the world’s oceans have been totally explored.
  4. Oceans have an average depth of two and a half miles (13200 ft).
  5. The ocean is three percent salt. Its salinity is estimated to be around 34 to 36 ppt (parts per thousand), whereas fresh water has a salinity of 0 ppt.
  6. Light can’t penetrate 300 feet through the ocean; this area that can never be touched by sunlight is called the “deep sea.”
  7. There is gold in the water! It is estimated that the world’s oceans and seas contain about twenty million tons of this precious metal.
  8. Marine biologists estimate that only two-thirds of marine life have been documented and studied. There are millions more species that remain to be discovered.
  9. “Rivers” and deep “lakes” can exist under the ocean. This can happen when salty water and hydrogen sulfide mix to form a dense brine that is heavier than regular seawater.
  10. There are kelp forests under the ocean that can rival even the lushest of forests on land. Kelp can grow up to two feet PER DAY, so these forests can grow on the ocean floor a hundred fifty feet deep, and reach the surface of the water.
  11. The world’s largest museum is the ocean. Underwater you can find relics, artifacts, ruins, and shipwrecks that number more than what you can find in the world’s museums combined.
  12. Aside from shipwrecks and other archaeological artifacts, you can also find a lost city underwater. Archaeologists discovered the lost city of Thonis/Heracleion off the coast of Egypt in 2000 that was long thought to be merely the stuff of legend.
  13. The deepest recorded point on the ocean floor is the Mariana Trench, with a depth of nearly 36,000 feet.
  14. The Mariana Trench can accommodate thirty Empire State Buildings (each at 1250 tall, including the spire) each standing one on top of another.
  15. The deepest dive by a human submersible vehicle was done in the Mariana Trench. This was accomplished by Jacques Piccard and Don Walsh (riding in research bathyscape) in 1960.
  16. Ninety percent of all volcanic activity on Earth happens in the ocean.
  17. Oceanic life forms began 3 billion years ago. In comparison, land-based creatures appeared only 400 million years ago.
  18. A mouthful of water from the ocean contains millions of bacteria and billions of viruses.
  19. Water pressure at the deepest point of the Mariana Trench can reach 1000 atm (atmospheric pressure).
  20. There are a lot of sea creatures that were able to adapt their bodies to withstand the high pressure found at the deepest corners of the ocean.
  21. The farthest that a human wearing a diving suit can reach under the ocean is 2000 feet.
  22. Mauna Kea is the highest mountain on the ocean! From the ocean floor, it stands about 33,400 feet high. Only 13,000 feet of its total height can be found above the water.