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EO INSIGHTS

Chinese Fishing Fleet and Grey-Zone Maritime Strategy

An Orbivis analysis of coordinated maritime behaviour, AIS limitations, and multi-sensor monitoring in the Indo-Pacific

🧭 Chinese Fishing Fleet Formations and Grey-Zone Maritime Strategy

January 2026 | Source: The New York Times
“Thousands of Chinese Fishing Boats Quietly Form Vast Sea Barriers”, The New York Times Investigative Team, January 2026.
Read the original investigation →

Background

In January 2026, The New York Times published an investigation describing unusually large, coordinated formations of Chinese fishing vessels operating in regional waters. Based on analysis of publicly available ship-tracking data and independent maritime intelligence validation, the reporting documented hundreds of vessels — in some areas numbering more than 1,000 — assembling into persistent, near-linear formations over extended periods.

While the investigation stopped short of attributing military command or intent, it highlighted the scale, geometric regularity, and persistence of the activity, noting that such behaviour departs markedly from typical commercial fishing patterns. The activity appeared to occur repeatedly across different locations within a short time frame, suggesting structured behaviour rather than coincidence.

What appears unusual

At an individual level, none of the vessels involved appeared exceptional. They were largely civilian fishing boats operating in waters where fishing activity is common. What distinguishes the reported events is not the vessels themselves, but their collective behaviour at scale.

Commercial fishing fleets are normally shaped by fish distribution, weather, fuel economics, and port access. They disperse, cluster irregularly, and move dynamically. By contrast, the formations described were spatially ordered, contiguous over long distances, and held with remarkable stability — characteristics that are difficult to reconcile with purely economic drivers.

From a maritime domain awareness perspective, this reframes the analytical problem. The challenge is no longer simply detecting vessels, but interpreting why large numbers of civilian actors are behaving in a coordinated, structured manner over time.

Why this may have remained largely unseen

A reasonable question is why such activity, derived from open data, was not more widely recognised earlier. The answer lies less in sensor availability and more in how maritime data is typically analysed.

Most operational maritime awareness systems are optimised for vessel-centric tasks: collision avoidance, compliance monitoring, safety, and near-real-time alerting. They are far less suited to identifying fleet-level structure, spatial regularity, and persistence across time. Without aggregation and historical baselines, highly structured behaviour can appear simply as dense traffic.

The limits and value of AIS

Automatic Identification System data underpins much open-source maritime analysis, but its limitations are well understood. AIS is cooperative, self-reported, uneven in quality, and incomplete. On its own, it cannot establish intent, command relationships, or coordination mechanisms.

At the same time, dismissing AIS because it is imperfect would be a mistake. Behavioural anomalies at sufficient scale do not require pristine data to be analytically meaningful. When hundreds of vessels exhibit similar movement patterns, spacing, and persistence over time, the signal emerges from collective behaviour, not individual track accuracy.

AIS-based analysis is indicative, not conclusive.

Independent verification beyond cooperative reporting

Analytical confidence improves when cooperative reporting is cross-checked against non-cooperative sensing. Synthetic Aperture Radar (SAR) plays a central role here. Unlike optical Earth observation, SAR provides all-weather, day-and-night coverage, making it particularly valuable in maritime environments where cloud cover and low light are persistent challenges.

While SAR may struggle to classify individual small vessels with precision, the analytical task in this case is not target identification but density, persistence, and spatial structure. SAR is well suited to confirming whether reported concentrations physically exist and whether formations persist over time.

Space-based radio-frequency (RF) sensing adds an electromagnetic dimension by detecting shipborne emissions. RF sensing can reveal activity even when positional broadcasts are absent, supporting persistence analysis and helping distinguish genuinely quiet waters from areas where activity is present but unreported.

Individually, none of these data sources is decisive. In combination, AIS + SAR + RF reduce reliance on any single dataset and strengthen confidence through cross-domain consistency.

A hypothetical stress test: AIS denial

Hypothetically, large-scale coordination conducted without AIS would significantly increase analytical uncertainty. Detection would depend primarily on non-cooperative sensing and persistence analysis, shifting the burden from behavioural interpretation to physical and electromagnetic observation.

This scenario is not presented as a prediction, but as a reminder that sensor dependency shapes analytical confidence, particularly in grey-zone maritime contexts where ambiguity is often deliberate.

Orbivis takeaway

This episode is unsettling not because it is fully understood, but because it illustrates how large-scale, structured civilian activity can exist in plain sight while resisting easy categorisation. The lesson is not about fishing vessels per se, nor about any single sensor. It is about the limits of compliance-oriented maritime awareness when confronted with scale, coordination, and persistence.

In grey-zone environments, ambiguity is not a failure of analysis — it is often the signal itself.

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