Hadal 1 ARV
Hadal 1 ARV (Hai-Dou 1 or 海斗 1 in Chinese, meaning Hadal 1) is a type of very little known unmanned underwater vehicle (UUV) built in the People's Republic of China (PRC). ARV stands for Autonomous Remotely-controlled Vehicle, an idea pioneered in China by Shenyang Institute of Automation (SIA) of Chinese Academy of Sciences (CAS), and SIA is also the developer of Hadal 1 ARV, and its predecessor Hadal ARV, as well as Arctic ARV, the predecessor of Hadal ARV. Hadal 1 and its predecessor Hadal, and earlier Arctic series ARVs are the Chinese  counterparts of Nereus hybrid unmanned underwater vehicle (UUV), because just like Nereus hybrid UUV, these ARVs can operate both as a AUV or a ROUV. The general designer of Hadal 1 ARV is Mr. Tang Yuan-Gui (唐元贵). The idea of having an UUV that can both operate in fully autonomous and in remotely controlled modes is due to the inherit shortcomings of both: When the UUV operates in greater depth, the tether cable would becoming heavy and limits the mobility of the UUV, so fully autonomous mode is preferred in such operations. However, when the UUV needs to operate  inside a wreckage or other complex structure, and need make adjustment in real time, the cost would have become prohibitive because mission planning software must include all possible scenarios, which may not cover everything, so when there are plenty opportunities of unexpected would happen, it would be far more cost effective to deploy a ROUV so human operators can adjust accordingly to the situation arose. Designing an UUV that can be both would be far more cost effective than having separate AUVs and ROUVs because one UUV can do the job for both. Earlier Arctic ARV series and Hadal ARVs  have proven the idea is feasible, and based on the experience gained, Hadal ARV was developed. The project formally started in July 2016, and development was completed in 2019. Like its predecessor Hadal ARV and earlier Arctic ARVs, Hadal 1 ARV is also having a rectangular hull, with a thruster on each side. Because Hadal 1 ARV has to operate as an AUV when required, it carried internal power source, i.e. batteries, so it only needs fiber-optic tether cable for data transmission, and thus eliminating the heavy power cable. Specification: