<P> The 2009 and 2010 maximal depths were not confirmed by the series of dives Nereus made to the bottom during an expedition in May--June 2009 . The direct descent measurements by the four expeditions which have reported from the bottom, have fixed depths in a narrow range from 10,916 m (Trieste) to 10,911 m (Kaikō), to 10,902 m (Nereus) to 10,898 m (Deepsea Challenger) Although an attempt was made to correlate locations, it could not be absolutely certain that Nereus (or the other descents) reached exactly the same points found to be maximally deep by the sonar / echo sounders of previous mapping expeditions, even though one of these echo soundings was made by Nereus' mothership . </P> <P> On 23 January 1960, the Swiss - designed Trieste, originally built in Italy and acquired by the U.S. Navy, descended to the ocean floor in the trench manned by Jacques Piccard (who co-designed the submersible along with his father, Auguste Piccard) and USN Lieutenant Don Walsh . Their crew compartment was inside a spherical pressure vessel, which was a heavy - duty replacement (of the Italian original) built by Krupp Steel Works of Essen, Germany . Their descent took almost five hours and the two men spent barely twenty minutes on the ocean floor before undertaking the three - hour - and - fifteen - minute ascent . Their early departure from the ocean floor was due to their concern over a crack in the outer window caused by the temperature differences during their descent . The measured depth at the bottom was measured with a manometer at 10,916 m (35,814 ft) ± 5 m (16 ft). </P> <P> On 26 March 2012 (local time), Canadian film director James Cameron made a solo manned descent in the DSV Deepsea Challenger to the bottom of the Challenger Deep . At approximately 05: 15 ChST on 26 March (19: 15 UTC on 25 March), the descent began . At 07: 52 ChST (21: 52 UTC), Deepsea Challenger arrived at the bottom . The descent lasted 2 hours and 36 minutes and the recorded depth was 10,898.4 metres (35,756 ft) when Deepsea Challenger touched down . Cameron had planned to spend about six hours near the ocean floor exploring but decided to start the ascent to the surface after only 2 hours and 34 minutes . The time on the bottom was shortened because a hydraulic fluid leak in the lines controlling the manipulator arm obscured the visibility out the only viewing port . It also caused the loss of the submersible's starboard thrusters . At around 12: 00 ChST (02: 00 UTC on 26 March), the Deepsea Challenger website says the sub resurfaced after a 90 - minute ascent, although Paul Allen's tweets indicate the ascent took only about 67 minutes . During a post-dive press conference Cameron said: "I landed on a very soft, almost gelatinous flat plain . Once I got my bearings, I drove across it for quite a distance...and finally worked my way up the slope ." The whole time, Cameron said, he didn't see any fish, or any living creatures more than an inch (2.54 cm) long: "The only free swimmers I saw were small amphipods"--shrimplike bottom - feeders . </P> <P> Several other manned expeditions are planned . These include: </P>

Has anyone been to the bottom of challenger deep