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.
Douglas C. Gordon
In 1998, Gordon participated in an expedition to the Tibetan river Tsangpo (named the Brahmaputra River in its lower course), sponsored by National Geographic. The team of middle-aged paddlers also included the brothers Jamie McEwan (Olympic slalom bronze medalist in 1972) and Tom McEwan (former slalom racer, with first descent experience including the Great Falls of the Potomac), and Roger Zbel. Three of them would use expedition kayaks, one a whitewater canoe. Gordon was the most experienced of the team, but all were considered expert river runners. A ground crew of five completed the expedition. Their plan was to accomplish the first descent of a 140-mile (225 km) section of the Tsangpo, passing the deepest river gorge on earth, the more than 4877 meter (16,000 ft) deep gorge between 7782-meter Namjagbarwa Feng and 7194-meter Gyala Peri. The paddlers had planned up to six weeks for the descent.