Quick Fact
The deepest point humans have ever reached underwater sits at 35,858 feet (10,935 meters) in the Challenger Deep, part of the Mariana Trench in the western Pacific Ocean. Coordinates: 11.35°N 142.2°E.
Where exactly is this deepest spot?
The Mariana Trench is the deepest known part of the world’s oceans, a crescent-shaped scar in the seabed near the Mariana Islands. This remote trench sits about 124 miles (200 km) east of the Mariana Islands, a U.S. territory in the Pacific. The trench forms where the Pacific Plate dives beneath the smaller Mariana Plate in a process called subduction. (Honestly, this is one of the most dramatic geological features on Earth.)
How deep is the Mariana Trench really?
| Feature | Measurement | Comparison |
|---|---|---|
| Maximum depth (Challenger Deep) | 35,858 feet (10,935 m) | Taller than Mount Everest is high (29,032 ft) |
| Average depth of world’s oceans | 12,400 feet (3,790 m) | Over 3.5 times deeper than the Grand Canyon’s average depth |
| Average depth of Caribbean Sea | 7,200 feet (2,200 m) | Slightly deeper than the height of Mount Fuji |
| Operational depth of U.S. nuclear submarines | Up to 800–1,500 feet (240–450 m) | Less than 3% of the Mariana Trench’s depth |
| Depth for safe free diving (most people) | 60 feet (18 m) | Equivalent to a six-story building underwater |
Has anyone actually made it to the bottom?
Yes, but only a handful of times. The Challenger Deep was first reached in 1960 by the Trieste, a Swiss-designed deep-sea submersible operated by the U.S. Navy. Swiss scientist Jacques Piccard and U.S. Navy Lieutenant Don Walsh spent about 20 minutes on the ocean floor, observing flatfish and shrimp—challenging the then-held belief that no life could exist at such depths. Decades later, in 2012, filmmaker James Cameron became the first person to reach the bottom solo in the Deepsea Challenger. In 2019, explorer Victor Vescovo descended to 35,853 feet, collecting new species and documenting plastic pollution even at the greatest depths.
The extreme pressure down there—over 1,000 times surface pressure—makes survival without specialized equipment impossible. A single square inch of surface area on the submersible experiences nearly 8 tons of pressure, a force equivalent to balancing a large SUV on a postage stamp NOAA Ocean Explorer.
What’s the pressure like at that depth?
Crushing. At the bottom of the Challenger Deep, pressure exceeds 1,000 times what we feel at the surface. Every square inch of a submersible’s hull bears nearly 8 tons of force—imagine parking a large SUV on a postage stamp NOAA Ocean Explorer. (That’s why only a few specially built vessels can handle it.)
Can submarines reach the bottom of the ocean?
Only a few specialized ones can. Most military and commercial submarines operate at much shallower depths—typically between 800 and 1,500 feet. The extreme pressure and technical challenges make reaching the Challenger Deep nearly impossible for standard submarines. (Honestly, this is why so few expeditions have succeeded.)
What kind of vessel can actually make it down there?
Only purpose-built deep-sea submersibles can reach those depths. The DSV Limiting Factor, for example, is one of the few capable vessels—it can carry two people and dive repeatedly to 11,000 meters. These aren’t submarines in the traditional sense; they’re more like tiny, ultra-reinforced capsules designed for extreme pressure WHOI.
How much does it cost to go down there?
Way more than most people can afford. As of 2026, private deep-sea expeditions to the Challenger Deep run between $500,000 and $1.5 million per person, and that doesn’t include the years of preparation needed BBC. (For most of us, this is firmly in the "dream only" category.)
Is there any life down there?
Surprisingly, yes. When Piccard and Walsh first reached the bottom in 1960, they spotted flatfish and shrimp—proof that life can survive in one of Earth’s most extreme environments. Later expeditions, like Vescovo’s in 2019, found new species and even documented plastic pollution at those depths. (Who knew garbage could sink that far?)
How do these expeditions actually work?
They’re carefully planned operations. Expeditions typically launch from Guam or Saipan, the nearest major ports about 200 miles west of the trench. Weather windows are critical—strong Pacific currents and the remote location make timing everything. Research vessels like the DSV Limiting Factor often partner with institutions such as the Woods Hole Oceanographic Institution to conduct these dives WHOI.
Can regular people visit the Mariana Trench?
Not anytime soon. Only a handful of manned expeditions have reached the Challenger Deep, and none are commercially available to the public. The cost, technical challenges, and sheer danger make it impractical for tourism—for now, at least.
What’s the biggest challenge of reaching the bottom?
Pressure is the main hurdle. The deeper you go, the more crushing the force becomes—over 1,000 times surface pressure at the Challenger Deep. Then there’s the isolation, the technical complexity of the submersibles, and the sheer cost of pulling off an expedition. (Honestly, this is why so few have tried.)
Has plastic pollution reached the Mariana Trench?
Unfortunately, yes. In 2019, explorer Victor Vescovo’s expedition found plastic waste, including a plastic bag and candy wrappers, at the bottom of the Challenger Deep. It’s a stark reminder that even the most remote places on Earth aren’t immune to human impact BBC.
What’s the future of deep-sea exploration?
More expeditions, better tech. Vessels like the DSV Limiting Factor are making it easier to reach extreme depths, and scientists continue pushing boundaries. As deep-sea tourism develops, we may see more private expeditions—but for now, the Challenger Deep remains one of the last true frontiers on Earth WHOI.
