Charting the Ocean's Depth

Where the human body implodes, and more milestones on the way to the bottom of the ocean

Surface
The weight of air exerts an imperceptible 14.7 pounds per square inch (psi) in all directionsYanyin
33 Feet
Exactly double the pressure at sea level. Even with a snorkel that reached the surface, the pressure on your body is too great to take a breath.Anna i Adria
500 Feet
Even with scuba gear, this is where most divers start to experience high-pressure neurological syndrome, which causes headache, tremors and muscle twitching. Nerves can't adapt to the increased pressure and malfunction.Steel City Hobbies
702 Feet
The free-dive record (no scuba gear), set by Austrian diver Herbert Nitsch in 2007. At this depth, his lungs were almost 95 percent collapsed and the rest filled with blood plasma.Vertical Blue
1,044 Feet
The depth at which South African diver Nuno Gomes set the scuba-dive record in 2005. Gomes was convulsing so badly that the respirator was coming loose from his mouth.Courtesy Sean French
1,500 Feet
Specific depths are classified, but nuclear attack subs typically operate in this territory.
6,500 Feet
Target depth for one of three versions of Deep Flight II Graham Hawkes hopes to sell. He also plans to offer a model that will reach 22,000 feet, and another capable of full-ocean depth.Nick Kaloterakis
12,500 Feet
Resting place of the RMS Titanic, which sunk in 1912Wikipedia Commons
21,000 Feet
Target maximum depth for the new Alvin, after final upgrades in 2015Courtesy of Woods Hole Oceanographic Institutions (WHOI)
35,800 Feet
At this depth, the pressure is more than 1,100 times that of the surface, or over 15,000 psi. Only two people have ever reached this depth, in 1960 in the Trieste. The window began to crack, so the record-setting trip was cut short after just 30 minutes on the bottom.U.S. Naval Historical Center Photograph