Thousands of Chinese fishing vessels assembling in precise, linear formations across vast stretches of the East China Sea in recent weeks have alarmed regional observers and maritime security experts, who say the movements appear far removed from ordinary commercial fishing and may signal coordinated activity by China’s state-backed Maritime Militia.
Shipping data and satellite imagery reviewed by analysts show fleets converging over multiple days into rigid geometric patterns extending hundreds of miles, remaining stationary for hours, and then dispersing with equal precision. The formations, unprecedented in scale, have sparked concern in Japan, Taiwan, and the United States, where experts see the episode as a possible test of Beijing’s ability to mobilize civilian vessels for strategic purposes without deploying overt military force.
China has rejected such interpretations, insisting the activity reflects normal winter fishing patterns. But specialists familiar with Chinese maritime behavior say the scale, coordination, and timing of the events strongly suggest state direction.
The first major incident occurred on December 25, when tracking data revealed more than 2,000 Chinese fishing vessels assembling off the coast of Shanghai. The ships formed two reverse L-shaped lines, each extending roughly 290 miles, according to maritime intelligence analysts.
Less than three weeks later, on January 11, another striking formation appeared. Nearly 1,500 vessels aligned into a single, straight line, stretching close to 300 miles across the same general waters of the East China Sea.
The movements were first reported by The New York Times and later corroborated by independent analysts using data from commercial ship-tracking services and satellite imagery.
“These are not random clusters,” said Harrison Prétat, deputy director of the Asia Maritime Transparency Initiative (AMTI) at the Center for Strategic and International Studies (CSIS). “In observing this type of data for years, I’ve never seen anything like this. My initial reaction was to question whether there was some kind of data error because the number of ships involved was far beyond anything previously observed.”
Data from Starboard Maritime Intelligence showed that in both instances, fishing vessels that had initially been dispersed across wide areas of the East China Sea gradually converged into a tightly defined zone over several days. Satellite imagery captured by Planet Labs on January 10 showed large numbers of ships moving in parallel toward the designated area.
Once in formation, the vessels ceased movement almost simultaneously, remaining largely idle for hours before dispersing in an equally organized fashion.
That behavior, experts say, is fundamentally incompatible with commercial fishing.
“Fishing vessels do not stop en masse in straight lines for extended periods,” said Andrew S. Erickson, a professor at the US Naval War College and one of the world’s leading experts on China’s Maritime Militia. Speaking in a personal capacity, Erickson described the formations as “a huge, precisely geo-coordinated flash mob.”
“The scale, geometry, coordination, and rapid assembly and dispersal of these formations are simply irreconcilable with normal fishing behavior,” he said.
The episode has renewed attention on China’s Maritime Militia, a vast network of ostensibly civilian fishing and commercial vessels that operate under state direction during sensitive operations.
According to the US Department of Defense, the militia is composed primarily of fishermen and maritime workers who retain civilian occupations but receive training, equipment, and subsidies from the Chinese government. In times of need, they can be activated to perform “official” missions that support the People’s Liberation Army Navy (PLAN) and the China Coast Guard.
“Beijing subsidizes various local and provincial commercial organizations to operate China Maritime Militia vessels to perform official missions on an ad hoc basis outside of their regular civilian commercial activities,” the Pentagon said in its most recent annual assessment of China’s military power.
Unlike naval or coast guard deployments, militia operations offer Beijing plausible deniability, allowing it to assert control over disputed waters while avoiding the escalatory risks associated with overt military action.
The Maritime Militia has long been active in the South China Sea, where it has harassed foreign fishing boats, shadowed naval vessels, and supported China’s expansive territorial claims. However, analysts say its operations have grown more visible and more assertive over the past decade.
In a February 2025 report, AMTI noted a shift in militia behavior, observing that many vessels were spending extended periods anchored at Chinese military outposts rather than at remote reefs where they previously pretended to fish.
“This suggests Chinese authorities are not pressuring vessel owners to maintain the crumbling façade of the militia as a legitimate fishing fleet,” the report said.
The East China Sea formations appear to reflect that same confidence, experts say — an indication that Beijing is increasingly willing to demonstrate its ability to mobilize civilian fleets for strategic purposes in full view of international observers.
The East China Sea is one of the most strategically sensitive maritime regions in Asia. It borders mainland China, Taiwan, Japan, and South Korea, and includes disputed areas such as the Senkaku/Diaoyu Islands, which are administered by Japan but claimed by China.
The waters are also critical shipping lanes for global trade and energy supplies, and they sit astride potential military routes in any conflict involving Taiwan.
While much attention has focused on China’s activities in the South China Sea, analysts say the East China Sea is equally important — particularly in scenarios involving Taiwan.
“It underscores the reality that this third PRC sea force engages in threatening gray zone operations and war-preparation activities not only in the South China Sea, but also in the East China Sea,” Erickson said. “The implications extend to Taiwan, Japan, regional security, and vital US interests.”
Experts caution that the precise purpose of the recent formations remains uncertain. However, several plausible explanations have emerged.
Prétat suggested the events may represent an early test of China’s ability to geographically organize large numbers of civilian vessels on short notice.
“It could be a proof-of-concept,” he said. “Demonstrating that authorities can rapidly assemble thousands of vessels into precise positions across a very large maritime space.”
Others see the formations as training or rehearsal, enabling militia units to practice receiving instructions, maintaining formation discipline, and coordinating dispersal — all critical skills in a crisis.
Erickson noted that the activity could also serve as a strategic signal, intended to be noticed by regional rivals and external powers.
“When you can put thousands of hulls in the water exactly where you want them, exactly when you want them, that sends a message,” he said.
The Pentagon has assessed that in a conflict scenario — particularly a Chinese invasion or blockade of Taiwan — the Maritime Militia could play a key supporting role.
Rather than engaging in direct combat, militia vessels could clutter key waterways, complicate foreign naval movements, and create legal and operational ambiguity for intervening forces.
Prétat warned that a more immediate concern could be the use of militia vessels in a quasi-blockade of Taiwan.
“They could assist in dissuading, rerouting, and ultimately stopping commercial traffic — cargo, fuel shipments, and critical supplies to Taiwan — without declaring a formal blockade,” he said.
Such actions would place foreign governments in a difficult position: confronting civilian-flagged vessels risks escalation and international backlash, while inaction could allow China to gradually tighten economic and logistical pressure.
China has firmly denied that the fishing fleets represent anything other than normal commercial activity.
In a statement to Business Insider, Liu Pengyu, a spokesperson for the Chinese embassy in Washington, said the East China Sea is a vital fishing area and that winter months typically see high concentrations of vessels.
“The period from November to February is peak season for winter fishing,” Liu said. “It is therefore normal to see a high concentration of fishing boats operating at sea during this time.”
He dismissed claims of militia involvement as politically motivated.
“Referring to Chinese fishermen as ‘maritime militia’ shows malicious intent driven by ulterior motives,” Liu said.
Despite Beijing’s denials, most maritime analysts remain unconvinced.
Commercial fishing, they note, does not require vessels to assemble into ruler-straight lines hundreds of miles long, nor to remain stationary for extended periods without deploying nets or changing positions.
“Fishing fleets compete with one another,” Prétat said. “They don’t cooperate in perfect geometric patterns.”
The events have also raised questions about how regional navies and coast guards should respond to similar situations in the future — particularly if such formations appear closer to disputed territories or critical sea lanes.
The massed fishing fleets may ultimately prove to be a harbinger of more frequent and more sophisticated gray zone operations in East Asian waters.
As China continues to expand its maritime reach, experts say the line between civilian and military activity at sea is becoming increasingly blurred — a challenge for regional stability and international maritime law.
“What we’re seeing is not just about fishing,” Erickson said. “It’s about control, signaling, and preparation — all conducted below the threshold of open conflict.”
For now, the formations have dispersed, leaving behind questions rather than answers. But analysts warn that the episode should be seen less as an anomaly and more as a preview.
“The takeaway,” Prétat said, “is that China has the ability to mobilize a massive civilian fleet quickly and precisely — and it wants others to know that.”
