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Chinese maritime research vessels have dramatically increased incursions into waters just 24 nautical miles off Taiwan’s coast, as Beijing signals its growing surveillance capabilities and collects data crucial for naval warfare.
The latest operations include an unprecedented sailing by China’s newest research ship, a drone carrier with links to the People’s Liberation Army, down the full length of Taiwan’s east coast in November.
The Zhu Hai Yun’s voyage was one of nine such intrusions since September, a sharp uptick from just two in each of the previous three years, according to tracking data of nearly 80 ships from Spire Global, a satellite data company, analysed by the Financial Times.
“This represents one more tool the People’s Republic of China is using in what I call the all-domain pressure campaign against Taiwan,” said Christopher Sharman, director of the China Maritime Studies Institute at the US Naval War College.
Under the UN Convention on the Law of the Sea, states may claim a contiguous zone up to 24 nautical miles from their coastline, giving them resource rights and jurisdiction over the surface and floor of that ocean area.
But due to Beijing’s sovereignty claim over Taiwan and its waters — which Beijing threatens to enforce militarily if Taipei resists submitting to its control indefinitely — Taipei cannot resort to protection by this international legal framework.
China frequently uses vessels operated by government and military-affiliated research institutes to assert its claims in disputed waters, sailing close to oil exploration sites inside the exclusive economic zones of Vietnam and Malaysia in the South China Sea, which Beijing claims almost in its entirety.
Maritime research vessels can measure water temperature, salinity and ocean currents and map the seabed — data which can be used for a broad range of scientific research, but also for naval warfare.
China has used such vessels to undertake extensive surveys close to Japan, the US Pacific territory of Guam and in the Indian Ocean, crucial areas for undersea warfare in a potential US-China conflict.
“Where the maritime research vessels go is where Chinese submarines will go in the future,” Sharman said.
The Zhu Hai Yun “really helps paint the picture of that undersea environment for China’s military”, he added. “It has implications for Taiwan and for any potential intervention. Operating east of Taiwan would certainly affect anyone approaching from further in the east.”
Analysts and government officials said the circumnavigation of Taiwan by the Zhu Hai Yun was unprecedented because of the ship’s cutting-edge technological capabilities, its clear links to the military and its route.
According to Chinese state media reports, the ship boasts an artificial intelligence-controlled autonomous navigation system — making it one of the world’s first such vessels designed to sail without a human crew — and can carry a fleet of 50 drones and autonomous submersibles.
In a report published on Monday, the Center for Strategic and International Studies think-tank said the Zhu Hai Yun was capable of conducting civilian and military survey work.
Satellite imagery shows that while under construction in July 2022, the Zhu Hai Yun moored beside a Type 056A corvette, a Chinese navy warship used for anti-submarine purposes.
The institute operating the drone carrier said its voyage was supervised by a researcher from the 704 Research Institute, which develops autonomous systems. The organisation was blacklisted by the US Department of Commerce for illegally buying US equipment to support the PLA.
Other researchers on board came from the 701 Research Institute, one of China’s main warship developers, and Sun Yat Sen University, which has close links to the military.
“China seeks to obfuscate and create this sort of ambiguity between the science, the commercial and the military,” said Matthew Funaiole, one of the authors of the CSIS report, pointing to the fact that some Chinese research ships switch off or spoof their transceiver signals.
While past incursions occurred mostly north, south and west of Taiwan, there is a more recent focus on the strategic waters to the east. The Zhu Hai Yun spent a day tracking the 24 nautical mile line east of the island, crossing it once off the city of Hualien, home to Taiwan’s most secure air force base, and again in the Bashi Channel, which Chinese ships need to pass through to reach the Pacific.
Taiwanese officials said after the Zhu Hai Yun was spotted on approach from the north on November 14, a coastguard ship shadowed it until it left radar range south-west of Taiwan the next day. The coastguard did not notice the Chinese vessel releasing drones into the water or air, according to one official.
Sharman said the Zhu Hai Yun could raise escalation risks if it operated fully autonomously close to Taiwan in the future. “I can see the PRC using this to penetrate the contiguous zone with a drone swarm to test Taiwan’s response and that would greatly increase the risk of an incident.”
Another Chinese research ship, the Da Yang, operated off Taiwan’s east coast from February 15 to 17, according to information from Taipei confirmed by ship tracking data.
Funaiole said the Da Yang had probable links to the PLA and frequently went “dark” while exploring contested areas. The vessel’s activity near the east coast of Taiwan was likely related to seabed critical mineral deposits, he added.
