Deepest remote-controlled (RC) device

The deepest point in the Earth’s oceans is the Challenger Deep, located in the Western Pacific Ocean near the island of Guam in the Mariana Trench. On 24 March 1995, Japanese research craft Kaikō became the first remotely controlled craft to visit this extreme depth. The maximum depth measured on the dive was 10,911.4 m (35,799 ft), making this the deepest dive for any unmanned submersible to date. On 29 May 2003, Kaikō was lost at sea during Typhoon Chan-Hom, when a steel secondary cable connecting it to the mothership at the surface broke, off near the coast of Shikoku Island. On 31 May 2009, research ROV Nereus became the third vessel to visit the bottom of the Challenger Deep, reaching a maximum recorded depth of 10,902 m (35,768 ft) – the second deepest a remote control submersible has ever been.