What is the name of the crewed submersible that made a solo dive to the Challenger Deep in 2012?

The crewed submersible that made a solo dive to the Challenger Deep in 2012 was Deepsea Challenger.

Australian-built Deepsea Challenger was designed for extreme-depth exploration and carried a single pilot inside a heavily reinforced pressure sphere. On 26 March 2012, Canadian filmmaker and explorer James Cameron piloted it alone to the floor of the Challenger Deep, in the Mariana Trench.

The descent took about two hours and 36 minutes, reaching a recorded depth of roughly 10,908 metres. Cameron spent several hours on the seafloor collecting observations and filming, although hydraulic problems and lost thrusters shortened the planned exploration. The dive was the first solo descent to the Challenger Deep and only the second crewed descent after Trieste’s 1960 expedition.

A common mix-up is confusing the vehicle with the location: Challenger Deep is the deepest-known point in Earth’s oceans, while Deepsea Challenger is the submersible. Shinkai 6500 is a Japanese research submersible, Alvin is a famous American deep-sea vehicle, and Trieste was the earlier bathyscaphe used in 1960.