China’s marine scientific research vessels are expanding their presence around Taiwan, and their activities extend far beyond the pursuit of scientific discovery. These operations serve to undermine Taiwan’s de facto independence and pressure the international community to accept Beijing’s claim of sovereignty over the island and its surrounding waters. This campaign of indirect pressure by the People’s Republic of China has grown more assertive since 2022. While much attention has focused on the People’s Liberation Army and the China Coast Guard, Chinese civilian survey ships often operate alongside them—quietly and in increasing numbers. Beijing views these vessels as valuable instruments for advancing its military and political goals. Though unarmed and crewed by civilian scientists and engineers rather than military personnel, their contribution remains deeply strategic: enhancing the PLA’s understanding of the maritime environment where potential conflict could unfold.
Chinese Activity Around Taiwan
The region in question lies at the convergence of waters claimed or administered by Taiwan, Japan, and the Philippines—territories that clearly implicate Taipei’s sovereignty concerns. Since Beijing asserts control over Taiwan and all adjacent seas, it has denounced recent moves toward bilateral talks between Manila and Tokyo aimed at delimiting their overlapping maritime boundaries east of Taiwan. Beijing condemned the initiative as a threat to its “maritime rights and interests,” dispatching several large coast guard vessels to demonstrate its stance. These patrol ships have maintained a continuous presence east of Taiwan since early June, drawing the majority of public scrutiny.
Nevertheless, China has also deployed multiple civilian research vessels to the same waters. Much of this survey work occurs within the maritime zone where Japan and the Philippines are conducting their negotiations. For instance, from June 9–18, the survey ship Da Yang Hao, operated by the China Ocean Mineral Resources R&D Association, conducted operations approximately 70 nautical miles east of Taiwan’s Orchid Island. Simultaneously, the Xiang Yang Hong 22 carried out surveys en route to its homeport following a mission in the Philippine Sea. Another vessel, the Jia Geng, owned by Xiamen University, completed three separate excursions into waters southeast of Taiwan during June and July.
Select People’s Republic of China Survey Activities, May 28 – July 22, 2026 (Source: www.marinetraffic.com, used with permission)
During June and July, Chinese survey activity intensified significantly around Taiwan, though such missions had been ongoing for some time within Taiwan’s exclusive economic zone and nearby waters. On the very day that Manila and Tokyo announced their planned talks, a Chinese acoustic research vessel—the Shiyan 1—was operating roughly 90 nautical miles southeast of Orchid Island. Earlier that month, from May 2 to 19, the research ship Tongji completed a full circumnavigation of Taiwan. While stationed east of the island, it navigated within just 30 nautical miles of the coast, prompting a response from the Taiwan Coast Guard, which dispatched a cutter to “expel” the intruder. During direct communication between the ships, the Tongji’s captain rejected Taiwan’s authority over its operations, proclaiming: “There is no Republic of China—only the People’s Republic of China.”
Beijing’s Objectives
Chinese marine science vessels operating near Taiwan are believed to pursue dual aims. First, their missions gather critical intelligence about the seafloor and water column, contributing directly to the PLA’s broader strategy of “battlefield preparation” (zhanchang zhunbei). While many of these efforts may superficially resemble legitimate global research initiatives, they align with known priorities of the Chinese military. For example, the Kuroshio Current flows through these eastern waters and has long attracted scientific study due to its influence on regional oceanography. However, mastery of this current also holds profound significance for undersea warfare, as thermal gradients shape sound propagation and enable submarines to evade detection. Such environmental data is integral to what the PLA calls “military oceanography” (junshi haiyangxue). Should hostilities arise over Taiwan, this accumulated knowledge would allow Chinese forces to seize operational advantages across surface, subsurface, and aerial domains.
In addition to mapping the water column, China’s civilian vessels are systematically surveying the seabed east of Taiwan. Though precise intent remains ambiguous, mounting evidence points toward inherently military applications. Patterns in navigation, historical precedents of PLA-led surveys, advanced sensor suites aboard these ships, institutional links between academia and defense, and the high-stakes diplomatic backdrop all suggest ulterior motives beneath ostensibly peaceful exploration. These activities likely constitute reconnaissance targeting fixed infrastructure—such as undersea cables linking Taiwan globally—and other strategic assets.
During another notable deployment, the research vessel Shen Hai 1—which serves as the mothership for the deep-sea submersible Jiaolong—operated roughly 50 nautical miles south of Taiwan’s coast near crucial undersea communication links connecting the island to the global internet grid. Such proximity raises alarms regarding potential threats to Taiwan’s digital lifelines.
Additionally, these vessels may be identifying foreign sensor networks deployed to monitor Chinese submarine movements along the First Island Chain—an asymmetric capability viewed as a vulnerability by Beijing. Detailed bathymetric charts generated through such surveys could also facilitate future mine-laying operations—a tactic endorsed in official Chinese naval doctrine. Thus, beneath the guise of scientific inquiry lies a sophisticated campaign of preparatory intelligence gathering.
A second motivation behind these surveys centers on legal warfare—exploiting ambiguities in international law to erode Taiwan’s legitimacy while asserting uncontested dominance over contested waters. Since June, this legal dimension has driven increased Chinese activity following Manila and Tokyo’s agreement to negotiate maritime boundaries without inviting Beijing. Conducting research without permission from Taipei constitutes a bold claim of sovereignty, leveraging domestic and international legal frameworks to legitimize exclusionary control.
Beijing argues that under both international and Chinese domestic law, no foreign vessel—regardless of declared purpose—can conduct any kind of marine survey in its claimed EEZ without prior consent. By carrying out unauthorized surveys in Taiwan’s waters, China makes a calculated bid to normalize its territorial claims through performative acts of sovereignty.
Yet responses from major powers like the United States—who have not formally recognized Taiwanese statehood—remain muted. This silence risks reinforcing Beijing’s growing assertiveness. Without vocal opposition, other nations implicitly validate China’s expansive interpretation of maritime law, setting a dangerous precedent for future disputes.
This dynamic poses a unique dilemma for Washington. The U.S. traditionally distinguishes between military and civilian oceanographic surveys under UNCLOS provisions, arguing that Article 56 grants coastal states jurisdiction only over non-military scientific endeavors. Military reconnaissance, Beijing counters, falls outside this scope—and thus requires no clearance.
However, distinguishing motives proves challenging when both forms of research produce identical datasets. If Taipei publicly challenged the legality of Chinese operations, it might appear to reinforce America’s longstanding stance that military surveys bypass traditional regulatory oversight—an outcome Beijing seeks to prevent.
Nevertheless, transparency trumps ambiguity. Calling out Beijing clarifies intentions, forcing a choice between legitimacy and defiance. Whether China continues ignoring objections or retreats behind territorial assertions, its hand reveals itself—and opens space for coordinated pushback from allies committed to preserving open seas.
Ultimately, silence enables Beijing’s legal offensive. Both Taipei and Washington must respond decisively to counter this evolving threat landscape.
Lessons for All
Effective resistance demands unified international pressure capable of shifting Beijing’s cost-benefit calculations. To meet this challenge, Taiwan and its partners should adopt parallel strategies rooted in principled engagement.
First, given that Chinese sources classify these missions as marine scientific research—an essential component of sovereignty narratives—Taipei should formally assert jurisdiction over every incident. Each unauthorized entry warrants formal protest, coupled with publication of detailed records documenting China’s transgressions. Regular monitoring, paired with intelligence sharing among democratic partners, strengthens collective awareness while undermining Beijing’s narrative of unchecked expansion.
Second, despite limited prospects for restoring pre-crisis stability, unaligned states should express concern over violations of Taipei’s rights. Failure to object signals tacit endorsement of Chinese dominance—an erosion of norms vital to maintaining peace across the Pacific Rim. Coordinated messaging amplifies deterrence effects, compelling Beijing to weigh escalation costs against diplomatic fallout.
Lastly, global stakeholders must acknowledge the dual nature of China’s maritime incursions—they signal either impending conflict or gradual strangulation of Taiwan’s autonomy. With civilian fleets increasingly weaponized for military gain—from concealed missile systems to covert amphibious assets—the line between commerce and combat blurs dangerously. Countries invested in regional security should deter Beijing from exploiting research platforms for sabotage, espionage, or mine warfare.
This imperative transcends Asia alone. Worldwide, Beijing deploys similar tactics to assert influence far beyond its borders. Unless nations recognize and resist these hybrid tactics—rooted in politics, law, and force—today’s confrontation over Taiwan becomes tomorrow’s template for coercion elsewhere.
Peter Alan Dutton, PhD, is a senior research scholar in law and senior fellow in the Paul Tsai China Center at Yale Law School.
Ryan D. Martinson is a member of the China Maritime Studies Institute at the U.S. Naval War College.
The views expressed in this article reflect the personal opinions of the authors alone and do not necessarily reflect the official views of the U.S. Department of the Navy, Department of Defense, or any other U.S. government entity.
**Please note, as a matter of house style, War on the Rocks will not use a different name for the U.S. Department of Defense until and unless the name is changed by statute by the U.S. Congress.
Image: Presidential Office Building via Wikimedia Commons
