<Li> Triton Submarines, a Florida - based company that designs and manufactures private submarines, whose vehicle, Triton 36000 / 3, will carry a crew of three to the seabed in 120 minutes; </Li> <Li> Virgin Oceanic, sponsored by Richard Branson's Virgin Group, is developing a submersible designed by Graham Hawkes, DeepFlight Challenger, with which the solo pilot will take 140 minutes to reach the seabed; </Li> <Li> DOER Marine, a San Francisco Bay Area based marine technology company established in 1992, that is developing a vehicle, Deepsearch (and Ocean Explorer HOV Unlimited), with some support from Google's Eric Schmidt with which a crew of two or three will take 90 minutes to reach the seabed, as the program Deep Search . </Li> <P> On 24 March 1995, the Japanese robotic deep - sea probe Kaikō broke the depth record for unmanned probes when it reached close to the surveyed bottom of the Challenger Deep . Created by the Japan Agency for Marine - Earth Science and Technology (JAMSTEC), it was one of the few unmanned deep - sea probes in operation that could dive deeper than 6,000 metres (20,000 ft). The manometer measured depth of 10,911 m (35,797 ft) ± 3 m (10 ft) at 11 ° 22.39 ′ N 142 ° 35.54 ′ E ﻿ / ﻿ 11.37317 ° N 142.59233 ° E ﻿ / 11.37317; 142.59233 for the Challenger Deep is believed to be the most accurate measurement taken yet . Kaikō also collected sediment cores containing marine organisms from the bottom of the deep . Kaikō made many unmanned descents to the Mariana Trench during three expeditions in 1995, 1996 and 1998 . The greatest depth measured by Kaikō in 1996 was 10,898 m (35,755 ft) at 11 ° 22.10 ′ N 142 ° 25.85 ′ E ﻿ / ﻿ 11.36833 ° N 142.43083 ° E ﻿ / 11.36833; 142.43083 and in 1998 10,907 m (35,784 ft) at 11 ° 22.95 ′ N 142 ° 12.42 ′ E ﻿ / ﻿ 11.38250 ° N 142.20700 ° E ﻿ / 11.38250; 142.20700 . It was lost at sea off Shikoku Island during Typhoon Chan - Hom on 29 May 2003 . </P>

What type of islands border deep sea trenches