The Application of the Haidou Autonomous and Remotely-operated Vehicle in the third Mariana Trench scientific expedition of China

From August to October of 2018, Haidou ARV participated in the third Mariana Trench scientific expedition of China. It carried out a total of 7 underwater trials in the Challenger Deep. The total working time in the bottom of Challenger Deep was 5h 47min. A lot of scientific data were got by Haidou ARV in the expedition, including HD video of the Challenger Deep, high-precision seabed depth measurement data and CTD observation data in the Challenger Deep. These observed data are of great significance for scientists to carry out scientific research on the Hadal zone in the future. This paper mainly describes the application of Haidou ARV in the third Mariana Trench scientific expedition of China and the scientific results of observation during the expedition.