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.
Operation Deep Water
Operation Deep Water took place as part of a series of concurrent NATO exercises held during the fall of 1957 which were the most ambitious military undertaking for NATO to date, involving more than 250,000 men, 300 ships, and 1,500 aircraft operating from Norway to Turkey. These other 1957 exercises were Operation Strikeback, which concentrated on NATO's eastern Atlantic/northern European flank; Operation Counter Punch involving Allied Forces Central Europe on the European mainland; Operation Stand Firm in the English Channel; Operation Sea Watch, a convoy escort exercise in the North Atlantic Ocean; and Operation Fend Off/Operation Fishplay, an anti-submarine exercise in the Greenland-Iceland-UK gap ("GIUK gap").