Lines on Water, Castles in the Sand

Filipino fishermen at Scarborough Shoal (Panatag Shoal/Bajo de Masinloc). Photo: GMA

July 20, 2026 – Quezon City, NCR, Philippines

Article by Whesley Samar

International Law and Historiography | West Philippine Sea

A sovereign state does not administer an open sea from behind a desk, and it does not acquire title to a reef simply by declaring the reef its own. Yet this is close to the shape of the modern “dispute” over the West Philippine Sea: two states offering competing narratives of "administration" that hold up very unevenly to scrutiny. 

If Part One traced how China's 1935 naming of Scarborough Shoal relied on British hydrographic charts, and Part Two argued that historical seasonal fishing does not, by itself, generate modern territorial title, Part Three examines the claim at the center of Beijing's position: that China has exercised continuous, systemic administration over these waters. The documentary record does not support the strong version of this claim. However, a rigorous accounting also requires acknowledging that the Philippine record, while considerably stronger, is not the seamless three century chain that is sometimes asserted either. The more defensible conclusion is narrower and, ultimately, more persuasive: the Philippines possesses the most consistent and best documented administrative paper trail of any claimant state, particularly from the mid twentieth century onward, and this asymmetry matters under international law even where the earlier record is genuinely mixed.

The Chinese claim of ancient, unbroken administration

The Hongwu Emperor of the Ming Dynasty, whose landmark 1371 imperial decree initiated the 'haijin' (sea prohibition) and fundamentally turned imperial policy inward, away from maritime governance. Photo: Shuge

If imperial China administered these waters since antiquity, the documentary record should show evidence of governance: tax rolls, magistrates, patrol logs. It largely does not, and the reason is instructive rather than incidental. For most of the Ming and Qing periods, the imperial state was not projecting power outward into the South China Sea; it was restricting its own population's access to the coast. The founding proclamation of this policy came in December 1371, when the Hongwu Emperor issued the edict that would set the tone for two centuries of Ming maritime policy, declaring, in a line frequently rendered in translation, that "not a single plank is allowed out to sea" (Ming Shilu). Under the Ming haijin (sea prohibition) that followed, and which was periodically intensified through the reigns of emperors such as Tianshun and Jiajing, private maritime trade was outlawed and, at its strictest, building an oceangoing vessel with more than two masts or trading abroad without state sanction could carry the death penalty. The Qing dynasty's early "Great Clearance" (1661 to 1683) went further still, forcibly relocating coastal populations inland by as much as thirty kilometers to sever support for Ming loyalist forces on Taiwan. These were not the policies of a state administering distant reefs; they were the policies of a state that, for long stretches, treated its own coastline as a security liability. This does not prove China had no historical presence in the sea. Chinese fishing communities operated there, sea ban enforcement was inconsistent, and smuggling networks persisted throughout. However, it substantially undercuts the claim of continuous state administration, which is the specific legal claim at issue.

The Philippine record, and its limits

A Navy Yard model of the Fragata Diana (preserved in the Museo Naval de Madrid). While no contemporary model of the Santa Lucía survives, this vessel represents the exact class of Spanish navy frigate commanded by Captain Francisco Riquelme during the landmark April 1800 hydrographic survey of Bajo de Masinloc. Photo: Todo a babor

The Philippine administrative record is considerably more consistent, though it did not begin as a clean, unbroken chain of sovereignty assertions. In 1800, the Spanish frigate Santa Lucía, under Captain Francisco Riquelme, conducted the first detailed hydrographic survey of the shoal then known as Bajo de Masinloc, and its findings were incorporated into the Derrotero del Archipiélago Filipino, the standard Spanish pilot's guide for the islands. This is a genuine administrative act, but it is worth being precise about what it does and does not establish. In 1937, when the Philippine Commonwealth government itself examined the historical record to determine whether it had grounds to formally claim the shoal, the head of the U.S. Coast and Geodetic Survey in Manila advised that the 1800 survey would, if anything, have conferred title on Spain rather than automatically on the Philippines, and that his office had no evidence any nation had yet formally asserted sovereignty over the feature (Bonnet, 2012). The Commonwealth government proceeded cautiously from there rather than treating the matter as already settled. This is not a fatal problem for the Philippine position. It is, if anything, a more honest one: it shows a state in 1937 taking the question of legal title seriously enough to investigate it, rather than simply asserting continuity it had not yet earned. This episode is documented in François Xavier Bonnet's institutional history of the dispute and is discussed further in Bill Hayton's work on the origins of the modern South China Sea claims map (Bonnet, 2012; Hayton, 2019).

What follows in the twentieth century is where the Philippine record becomes genuinely strong. Following the 1898 Treaty of Paris, American colonial administration mapped and regulated Philippine waters, and the 1939 Census atlas documented Scarborough Shoal as national territory. The Philippines conducted an oceanographic survey of the shoal in 1957 and raised the Philippine flag there in 1965. In 1963, the Philippine government built and operated a steel bar lighthouse on the shoal, a physical, continuously maintained structure that constitutes a concrete act of state administration in a way that cartographic notation alone does not. Taken together, this is not a case of a state asserting ancient, unbroken sovereignty; it is a case of a state building an increasingly well documented administrative record over nearly a century and a half, most convincingly in the period after 1898.

Green-washed lawfare and the manufacture of "administration" since 2016

The floating research platform deployed inside Scarborough Shoal in May 2026. Billed by Beijing as an ecological study facility, its strategic placement triggered intense diplomatic pushback from Manila over the creeping manufacture of a physical Chinese presence. Photo: Rappler

Having lost the 2016 arbitral case decisively, Beijing has since relied on a newer form of administrative assertion: environmental designation paired with physical presence. In September 2025, China's State Council approved a 3,523.67 hectare "Huangyan Dao National Nature Reserve," managed under Sansha City in Hainan Province, with a restricted "core zone" and an "experimental zone" framed around coral reef protection (CGTN, 2025; NIICE Nepal, 2025). Framed on its own terms, this is presented by Chinese state media as a conservation measure. It is worth noting, however, that the same period saw large scale, China linked fishing operations reported to have damaged the shoal's reef systems while harvesting giant clams, a tension between the conservation framing and the on the ground activity that Philippine and independent observers have raised directly (Asian Century Journal, 2026).

In May 2026, Philippine authorities reported discovering a roughly 30 square meter floating structure anchored in the shoal's inner lagoon. Chinese state media described it as a temporary research platform operated by the South China Sea Institute of Oceanology, intended to study reef resilience (Fan & Liu, 2026; Feng, 2026). Manila registered a formal diplomatic protest, expressing concern that the structure could be a precursor to permanent infrastructure. The vessel Yue Zhan Yu Ke 6 was subsequently dismantled and removed the platform on June 16, 2026 (Crypto Briefing, 2026). The competing accounts here should be read as exactly that, a Chinese government characterization and a Philippine security concern, not a settled fact about intent, but the sequence itself (environmental designation, followed by a physical installation, followed by removal only after diplomatic pressure) is difficult to read as unrelated to the broader contest over administrative presence.

This is backed by a substantial and growing physical presence. In the first half of 2026, China Coast Guard vessels logged 933 ship days patrolling Scarborough Shoal, approaching the 1,099 ship days recorded across all of 2025, maintaining an active perimeter extending up to 30 nautical miles from the shoal alongside a continuous six-to eight-vessel maritime militia presence (Daily Tribune, 2026). The Philippine Coast Guard and Bureau of Fisheries and Aquatic Resources have responded by increasing their own presence to an average of 43 ship days per month in the same period, a 43 percent increase over 2025 (Daily Tribune, 2026).

What does this mean under international law?

The Japanese Room inside the Peace Palace at The Hague, seat of the Permanent Court of Arbitration. Under modern international law, a state's unilateral administrative decrees and physical posturing hold no legal weight when measured against the binding codifications of the United Nations Convention on the Law of the Sea (UNCLOS). Photo: Peace Palace

Beijing's strongest available counter argument deserves to be stated plainly: sovereignty over remote, uninhabitable maritime features has historically been asserted by states through naming, cartographic inclusion, and periodic patrol rather than permanent occupation, and China would argue its nature reserve and research activities are simply a modern expression of that same kind of administrative act. The difficulty with this argument is not that administration must be constant to count. It is that the underlying claim to have exercised it continuously since antiquity is not supported by the documentary record, and that under UNCLOS, administrative or environmental designations over a submerged reef or a rock incapable of sustaining human habitation do not, on their own, generate maritime entitlement. No nature reserve declaration and no volume of coast guard patrols can retroactively cure a claim the 2016 Tribunal already found wanting in law. What the record actually shows is not a millennium of Chinese governance meeting a mirror image millennium of Philippine governance. It is a genuinely mixed and evolving Philippine administrative record that becomes markedly stronger and more consistent from the late nineteenth century onward, set against a Chinese record whose claim to continuity does not survive contact with the haijin era. That asymmetry, honestly stated, is the more durable argument, because it does not require the historical record to be cleaner than it actually is.

What comes next?

Three pillars have now fallen: naming, fishing, and administration, each tested against UNCLOS and found wanting. However, Beijing's position has never rested on winning inside that framework. Chinese legal writing argues history is itself an independent source of title, one that predates UNCLOS and survives a tribunal's refusal to recognize it. On this view, the nine-dash line is not a claim awaiting legal validation; it is a historical fact the Convention arrived too late to erase. Part Four takes that argument on its own terms and asks whether it survives scrutiny any better than the pillars that came before it.

References

Asian Century Journal. (2026, February 8). Scarborough nature reserve: AI not intelligent after all. https://asiancenturyph.com/2026/02/08/scarborough-nature-reserve-ai-not-intelligent-after-all/

Bonnet, F. X. (2012). Geopolitics of Scarborough Shoal (IRASEC Discussion Paper No. 14). Research Institute on Contemporary Southeast Asia. chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/https://www.irasec.com/IMG/UserFiles/Files/04_Publications/Notes/Geopolitics_of_Scarborough_Shoal.pdf

CGTN. (2025, September 11). Huangyan Dao reserve underlines China's marine protection efforts. https://news.cgtn.com/news/2025-09-11/Huangyan-Dao-reserve-underlines-China-s-marine-protection-efforts-1GA4Vgi2ZvW/p.html

Crypto Briefing. (2026, June 24). China deploys floating platform at Scarborough Shoal, raising concerns of expanded control. https://cryptobriefing.com/china-floating-platform-scarborough-shoal/

Daily Tribune. (2026, July 5). CCG presence at Scarborough Shoal nearly matches 2025 total in first half of 2026, AMTI. https://tribune.net.ph/2026/07/05/ccg-presence-at-scarborough-shoal-nearly-matches-2025-total-in-first-half-of-2026-amti

Fan, W., & Liu, X. (2026, June 11). Exclusive: Alleged 'new structure' on China's Huangyan Dao is a temporary research facility; Chinese expert urges Philippines to stop the hype. Global Times. https://www.globaltimes.cn/page/202606/1363310.shtml

Feng, F. (2026, June 15). Philippines' renewed hype over Huangyan Dao research platform shows frustration, diverts attention from domestic problems: experts. Global Times. https://www.globaltimes.cn/page/202606/1363539.shtml

Hayton, B. (2019). The modern origins of China's South China Sea claims: Maps, misunderstandings, and the maritime geobody. Modern China. https://journals.sagepub.com/doi/10.1177/0097700418771678

Maritime Executive. (2025, June 11). Philippines raise alarm over new Chinese structures at Scarborough Shoal. https://maritime-executive.com/article/philippines-raise-alarm-over-new-chinese-structures-at-scarborough-shoal

NIICE Nepal. (2025, September 18). China's national nature reserves in the South China Sea. https://niice.org.np/archives/11683