China Is Mapping the Seabed to Unlock a New Edge in Warfare

China is rapidly expanding ocean exploration in waters far beyond its shores, sending out a fleet of vessels whose research offers Beijing valuable military intelligence as it expands its naval reach and menaces U.S. allies.

- Austin Ramzy

China's fleet has triggered protests from Japan, India, and others, but that hasn't stopped Beijing from launching long missions to map the sea floor. The data they obtain has numerous applications, from science to the emerging industry of deep-sea mining, but it is the government's commandeering of civilian research for military use that threatens American allies.

"If that data may have some value to the Chinese military and they want access to it, they're going to get it," said Matthew Funaiole, senior fellow in the China Power Project at the Center for Strategic and International Studies. "There's no firewall in place."

India's navy drove a Chinese research ship away in 2019, but more have returned. In recent weeks, two of China's most advanced research vessels, the Xiang Yang Hong 01 and the newer Dong Fang Hong 3, have conducted lawn-mower-style sweeps across vast stretches of the eastern Indian Ocean.

Chinese civilian vessels are pursuing expeditions around the world—there are as many as a dozen or so active at any given time. The data they gather, including on currents, temperature, and salinity, can have an array of applications. Detailed scanning of the seabed, for instance, can provide information about the visibility of naval mines and the accuracy of sonar.

The surveys can also help determine what minerals could be extracted. Beijing is already dominating the race to obtain the minerals critical for defense, electric vehicles, and other technologies, and it is keeping ahead of Western commercial efforts to catch up.

In a study of 64 research and survey vessels operated by Chinese agencies, law enforcement, universities, and state-owned enterprises, CSIS found more than 80% had links or showed behavior—such as visiting military ports—that suggested they were involved in "advancing Beijing's geopolitical agenda."