What is the maximum depth a submarine can go underwater?
The deepest point in the oceans is Challenger Deep with a depth of approximately 36,000 feet (11,000 meters). Challenger deep is located at the southern end of the Mariana Trench near the Mariana Islands group, in the Pacific Ocean.
A Swiss-designed deep-diving research boat known as Bathyscaphe Trieste had reached the record-breaking depth of about 10,911 meters (35,797 ft) in the Challenger Deep on January 23, 1960. This is the last point a submarine could reach. Two more descents followed the Bathyscaphe Trieste expedition. One was unmanned ROVs Kaiko in 1995 and another was Nereus in 2009.The depth measured by them were almost similar, i.e. 10,902 to 10,916 meters.