Chinese Manned, Unmanned Submersibles Survey the World’s Deepest Spot

Chinese-made unmanned submersible Haidou-1 and the manned Striver (Fendouzhe) conducted a large-scale near-bottom topographic survey in the western depression of the Challenger Deep during a scientific expedition to the Mariana Trench.

With this, the Haidou-1 became the first in the world to survey the Challenger Deep, the world’s deepest spot at approximately 11,000m.

The coordinated work of the unmanned and manned submersibles this time marks a new phase in China's deep-sea exploration field, experts said. Taking advantage of each of their strengths, such as Haidou-1's capability to detect large areas of the seabed and Striver's fine filming technologies and robotic arm sampling, the efficiency of deep-sea expeditions will further be enhanced, the Global Times reported recently.

The fish-like, autonomous remotely operated vehicle of Haidou-1 was developed by the Shenyang Institute of Automation under the Chinese Academy of Sciences.

Tang Yuangui, chief engineer of the vehicle, said it has three control modes - autonomous mode, remote control mode and mixed mode - enabling it to flexibly respond to extreme marine conditions of all depths, and carry out scientific research activities, including abyssal exploration, the China Central Television (CCTV) reported.

Haidou-1 could be used in target locating, seafloor topography detection, real-time image broadcasting and identification of target objects. It has broken several world records for unmanned submersibles, including the first full-coverage acoustic cruise of the western depression of the Challenger Deep, a diving depth of 10,908m, and near-seabed navigation distance of more than 14km, according to Tang in October.

Meanwhile, the Striver has also completed its first regular exploration application and conducted trials at 10,000 meters underwater for deep-sea equipment, CCTV reported. 

The Striver has made 28 dives from 7,700-10,900m deep so far, seven of which have exceeded the 10,000m mark. It also conducted research operations in the deepest area of the Challenger Deep, with 18 scientists participating in the dives for the first time.

Zhang Yu, a researcher of marine microbiology at Shanghai Jiao Tong University, noted that the Striver is mainly tasked with two things, providing support for deep-sea equipment trials and for scientists on diving voyages to conduct comprehensive studies, data and sample collections in geology, biology and chemistry.

The manned submersible successfully passed its comprehensive performance evaluation in July, and set a national record by diving to a depth of 10,909m in the Mariana Trench in November 2020.