Bathyscaphe Trieste
On 23 January 1960, she reached the ocean floor in the Challenger Deep (the deepest southern part of the Mariana Trench), carrying Jacques Piccard and Don Walsh. This was the first time a vessel, manned or unmanned, had reached the deepest known point of the Earth's oceans. The onboard systems indicated a depth of , although this was revised later to ; fairly recently, more accurate measurements have found Challenger Deep to be between and deep.
FNRS-2
The FNRS-2 was the first bathyscaphe. It was created by Auguste Piccard. Work started in 1937 but was interrupted by World War II. The deep-diving submarine was finished in 1948. The bathyscaphe was named after the Belgian Fonds National de la Recherche Scientifique (FNRS), the funding organization for the venture. FNRS also funded the FNRS-1 which was a balloon that set a world altitude record, also built by Piccard. The FNRS-2 set world diving records, besting those of the bathyspheres, as no unwieldy cable was required for diving. It was in turn bested by a more refined version of itself, the bathyscaphe "Trieste".