None Deeper

If I ever get down to the Smithsonian, the Trieste will be the first item on my list. In 1960, it dove to over 35,000 feet, the world' s deepest dive in the Mariana Trench, near Guam. In over 40 years this feat has never been repeated.

Most significant of these was "PROJECT NEKTON" in which TRIESTE conducted a series of seven dives including three deep dives, climaxing on January 23, 1960 in a 35,800 foot descent into the "Challenger Deep". This abyss, the deepest known spot in the earth's oceans, had never been penetrated by a manned vehicle. The record set that day stands alone today. For this series of dives, TRIESTE was fitted with a new pressure sphere, manufactured by the "Krupp Werke (works)" of Germany and designed for operation to 36,000 feet. That dive gained, not only a record which cannot be exceeded but, world wide recognition of the TRIESTE and its occupants on that dive, Jacques Piccard, son of Auguste Piccard and Navy lieutenant Don Walsh...

Also check out this multimedia presentation at PBS.org.
Zork out.