How Deep Is the Ocean

• The ocean is significantly deeper than the highest point on Earth’s surface. 
• The Titanic is located deeper than the Cuvier beaked whale will venture, the deepest diving mammal.
• But even the Titanic wreck doesn’t come close to the deepest crewed mission that reached 35,839 feet in 2019.
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This article is primarily transcribed from a 2017 Insider video on “This incredible animation shows how deep the ocean really is.”  Some of the information has been updated.

Just how deep does the ocean go? If you took the highest point on land and submerged it, you would still have more than a mile between you and the deepest point in the ocean. 

The oceans harbor 99% of all living space on Earth and have enough water to fill a bathtub that’s 685 miles long, on each side. To compare, the state of California is about 720 miles long.

For scale, the average height of a human is about one-sixteenth the typical length of a blue whale — the largest animal on Earth. Blue whales usually hunt at depths of around 330 feet, within the well-lit zone of the ocean.

Deeper down, at 700 feet, the USS Triton became the first submarine to circumnavigate the Earth in 1960. 

At 831 feet we reach the deepest free dive in recorded history by Austrian-born diver Herbert Nitsch. Down here, the pressure is 26 times greater than at the surface, which would crush most human lungs. But blue whales manage it diving to a max depth of 1,640 feet where they hunt giant squid. 

During his descent, Nitsch developed severe decompression syndrome which led to multiple brain strokes. However, he reached the surface, recovered inside a hyperbaric chamber, and ultimately survived to tell the tale.

At 2,400 feet we reach the danger zone for modern nuclear attack submarines. Any deeper and the submarine’s haul would implode. 

Reaching 2,722 feet down is where the tip of the world’s tallest building — the Burj Khalifa — would reach. A little farther at 3,280 feet, we’re deep enough that sunlight can’t reach us. We’ve now entered the midnight zone. 

Many animals down here can’t see, such as the eyeless shrimp at 7,500 feet which thrive near scalding hot underwater volcanoes. 

At this depth, temperatures are just a few degrees above freezing, but the water around hydrothermal vents can heat up to 800 degrees Fahrenheit. 

Around 9,816 feet is the deepest any mammal has been recorded swimming, the Cuvier beaked whale. 

But not even the Cuvier beaked whale could explore the RMS Titanic, which rests at a staggering depth of 12,500 feet. 

The pressure is now 378 times greater than at the surface. Yet you can still find life like the fangtooth hagfish and dumbo octopus, the deepest living octopus on Earth. 

At 20,000 feet is the hadal zone, an area designated for the ocean’s deepest trenches, like the Mariana Trench. 

If you tipped Mt. Everest into the Mariana Trench, its summit would reach down to 29,029 feet. That still doesn’t compare to the two deepest crewed missions in history. 

In 1960, oceanographer Jacques Piccard and Lt. Don Walsh descended to the lowest point on Earth, Challenger Deep, at a record 25,979 feet below the surface. 

For decades, they held the record until explorer Victor Vescovo came along in 2019. Vescovo made three dives to Challenger Deep that year, and set the new record on the third dive, reaching a depth of 35,839 feet.

Scientists have sent half a dozen unmanned submersibles to explore Challenger Deep including Kaiko, which collected over 350 species on the seafloor between 1995 and 2003. But scientists estimate there are potentially thousands of marine species we have yet to discover. 

Humans have explored an estimated 5% to 10% of Earth’s oceans. We’ve only just begun to understand the deep, dark world that flows beneath us. 

Watch the original video here: