On 23 January 1960, Swiss oceanographer Jacques Piccard and US Navy Lieutenant Don Walsh made history by descending in the bathyscaphe Trieste to the deepest part of the oceans, the Mariana Trench in the Pacific Ocean. Fixed to the exterior was an experimental Rolex watch, the Deep Sea Special, which was specially designed to withstand the extreme pressure at 10,916m/35,814ft. When the Trieste resurfaced after some eight and a half hours, the watch was found to have kept perfect time.