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South China Sea, explained.

A China Coast Guard boat patrolling over a reef at Scarborough Shoal in April (Chen Bin/Xinhua via Getty Images)
A quiet chart deposit won’t move a single China Coast Guard ship, but it builds a legal record Beijing can’t easily erase.
About the author
Lowell Bautista
Lowell Bautista is Associate Professor of Law at Western Sydney University and an expert in public international law and the law of the sea, with a focus on maritime disputes in the Asia-Pacific.
In the South China Sea, power is usually measured in ships, patrols and presence. In July, the Philippines opened a quieter front: the legal record.
By depositing Chart No. 1567 with the United Nations (Opens in new window), setting out the baselines, territorial sea and contiguous zone of Bajo de Masinloc (Opens in new window), or Scarborough Shoal, Manila made a quiet but potentially enduring move. No ships changed course. No water cannon fired. Yet the filing may outlast the confrontations that dominate the headlines, shaping not who controls the waters today, but whose legal position endures tomorrow.
Manila casts the filing as routine: a technical measure under Article 16 of UNCLOS (Opens in new window), which requires coastal states to publicise the baselines from which maritime zones are measured. Accurate, yes, but strikingly understated.
Many states delay such deposits for years or make them quietly, without fanfare. The Philippines did neither. It expressly linked the chart to its Maritime Zones Act (Opens in new window) and to the 2016 South China Sea Arbitral Award (Opens in new window).
In a dispute defined by coast guard confrontations and military posturing, the Philippines has chosen a different form of competition.
The filing creates no new rights. It does not confer entitlement, and it certainly does not settle sovereignty over Scarborough Shoal, a question UNCLOS was never designed to answer, and one the 2016 tribunal expressly left untouched. What the chart does is subtler, but strategically important: it takes an existing Philippine legal position and makes it official, durable and citable.
Once deposited with the UN, the chart enters the international record in a way a press release cannot. It remains there, available to states, lawyers, historians and tribunals long after today’s headlines have faded.
This is the logic behind what might be called lawfare by accretion: not one dramatic legal strike, but the steady accumulation of documentation, legislation, and institutional acts that, over time, builds a formidable legal record. Since the 2016 award, Manila has pursued this strategy through the Maritime Zones Act, the Archipelagic Sea Lanes Act (Opens in new window), a succession of diplomatic notes (Opens in new window), and now chart deposits. Each step is modest alone; together, they reinforce a consistent legal position that becomes harder to ignore with every addition.

The Philippine delegation presenting the official copy of NAMRIA Chart No. 1567 entitled “Bajo de Masinloc and Approach” with DOALOS Deputy Director Alice Hicuburundi, centre left (DFA Philippines)
That same week the Scarborough chart was lodged, Philippine officials presented the country’s long-pending partial submission on an extended continental shelf in the West Palawan Region (Opens in new window) to the UN Commission on the Limits of the Continental Shelf, advancing a claim more than a decade in the making. Two UNCLOS-based moves in a single week are not coincidence.
The 2016 tribunal ruled that Scarborough Shoal is a “rock” under Article 121(3) of UNCLOS, entitled to a territorial sea but no exclusive economic zone or continental shelf, and that South China Sea maritime entitlements must rest on UNCLOS rather than expansive historic claims (Opens in new window). The new chart translates that ruling into state practice.
There is something almost provocative in the restraint. In a dispute defined by coast guard confrontations and military posturing, the Philippines has chosen a different form of competition: to align its claims carefully and publicly with international law, and challenge other claimants to do the same rather than compete on naval power alone.
Predictably, China rejected the filing (Opens in new window), reasserting its own claim over what it calls Huangyan Dao and backing that position with joint patrols involving the People's Liberation Army and the China Coast Guard (Opens in new window). That response lays bare the asymmetry at the heart of this contest. Beijing’s rebuttal is backed by hulls in the water, while Manila’s claim is backed by a document in a UN registry. Sceptics are right that, in the near term, this is no contest at all: a chart does not reroute a single coast guard cutter, and China’s operational presence around the shoal is unlikely to change because of a filing in New York.
International law, however, operates on a different clock from a coast guard patrol. Its force is cumulative, built through protest, practice, precedent and the patient construction of a record. A chart deposited today may become evidence cited years from now, and a diplomatic note may later help establish consistent state practice. Beijing’s physical dominance around Scarborough Shoal is a fact of the present. Manila’s strategy is to ensure that physical control does not harden, through silence or acquiescence, into legal legitimacy. Its filings are investments in a future legal record: quiet, incremental, but potentially consequential.
For Australia and other countries, the significance extends well beyond Scarborough Shoal. The Philippine approach offers a model for contesting asymmetric power without matching it ship for ship: document relentlessly, protest consistently, invoke the law precisely, and build the record. But Manila must sustain that discipline, asserting its rights, contesting contrary claims and avoiding acquiescence. States such as Australia must, in turn, cite that record, uphold the relevant rules of international law and act consistently with them when it counts. Beijing may command the waters around Scarborough Shoal today. It does not command the law.