China’s unmanned submersibles now rank as the world’s largest, with last year’s military parade showcasing two models (HSU001 and AJX002) approaching 20 metres (66 feet) in length.
Satellite imagery analysed by Western media also revealed a classified variant exceeding 40 metres at a naval installation, triggering international concern – particularly in the United States.
These dimensions created a brand new class of drones known as extra-extra-large uncrewed underwater vehicles (XXLUUVs). They dwarf America’s largest unmanned underwater vehicle, the 15-metre “Orca”.
US defence experts responded to the developments with stark warnings about vulnerabilities along America’s West Coast, with some analysts designating Seattle, Oakland, Los Angeles and the Panama Canal as potential targets.
Yan Zheping, China’s leading submersible authority and director of unmanned systems at Harbin Engineering University’s College of Intelligent Systems Science and Engineering, addressed these concerns in peer-reviewed research published last month.
China’s ultra large models “prioritise regional security and near-coast defensive reconnaissance while simultaneously supporting civilian research and environmental monitoring”, Yan wrote in his paper for the Chinese Journal of Ship Research, clarifying the vessels’ strategic purpose to the public for the first time.
This indicates these deep-sea giants would mainly counter US military operations in potential Taiwan Strait or South China Sea contingencies, instead of conducting trans-Pacific strikes.




