According to AIS data, the research vessel Zhong Shan Da Xue sailed through the South China Sea from May to June 2025. However, Sun Yat-sen University declared that the vessel was active in the South China Sea in August 2025, which contradicts the AIS data. The announcement stated that Sun Yat-sen University had conducted sea-trials of Haiqin, a remotely operated vehicle (ROV) capable of operating at depths of up to 6,000 meters, and that Zhong Shan Da Xue had deployed the Haidou-1 autonomous underwater vehicle (AUV) at the same time. This marked the first scientific survey conducted by coordinating two different unmanned vehicles via a single support ship¹⁴.

Why use a warship when a fishing boat will do? Civilian hulls buy deniability, and each cable cut is small enough to absorb. That a feature not a bug. We spill the tea.

“China prefers ‘invisible hybrid warfare’ (隐形混合战) over kinetic warfare.  Covert irregular warfare enables China the means to quietly overwhelm its targets not only physically but economically and politically as well – all without firing a shot.  The use of civilian fishing vessels not only provide plausible deniability but legitimizes China’s claims and salami-slicing tactics as lawful and just.”

Chinese research ships survey seabeds for science and resources. The same data says where submarines can hide, and where they cannot. Dual-use by design.