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.
Diving watch
In 1960 a Rolex Deep Sea Special prototype diving watch attached to the hull of the bathyscaphe "Trieste" reached a record depth of of seawater during a descent to the bottom of Challenger Deep, the deepest surveyed point in the oceans. The watch survived and tested as having functioned normally during its descent and ascent. The Deep Sea Special was a technology demonstration and marketing project, and the watch never went into production.