How far down can a submersible go?

* Corrected - More than 35,000 feet below the surface. The maximum depth of a submersible is limited by many factors, but the most important is the strength and integrity of its hull. At 35,000 feet, the pressure is approximately 15,750 pounds per square inch. In 2012, the Deepsea Challenger reached the bottom of the Marianas Trench, the deepest area on Earth, at a depth of more than 35,000 feet.