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).
[1][2][3][4][5] A UUV able to switch between fully autonomous and remotely controlled modes is advantageous.
However, when the UUV needs to operate inside wreckage or other complex structures, 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.
[1][2][3][4][5] Because Hadal 1 ARV has to operate as an AUV when required, it carries internal power source, i.e. batteries, so it only needs a fiber-optic tether cable for data transmission,[1][2][3][4][5][6][7][9] and thus eliminates the heavy power cable.