West Philippine Sea, Maritime Zones, and the Rule of Law

News hook: In May 2026, President Ferdinand Marcos Jr. addressed Japan's parliament and stated that seas must be governed by rules, not force — invoking the 2016 Arbitral Award and UNCLOS as the legal foundation for the Philippines' position in the South China Sea. The speech renewed public interest in two landmark 2024 Philippine laws — the Maritime Zones Act (RA 12064) and the Archipelagic Sea Lanes Act (RA 12065) — that translated international maritime law into domestic statutes for the first time.

Legal question

What do Republic Act No. 12064 (Philippine Maritime Zones Act) and Republic Act No. 12065 (Philippine Archipelagic Sea Lanes Act) actually say, how do they relate to UNCLOS and the 2016 Arbitral Award, and what is the legal distinction between sovereignty and sovereign rights in the West Philippine Sea?

Applicable laws and rules

Republic Act No. 12064 (Philippine Maritime Zones Act of 2024) — defines and declares the Philippines' maritime zones consistent with UNCLOS: territorial sea (12 nautical miles), contiguous zone (24 nm), Exclusive Economic Zone (200 nm), continental shelf, and extended continental shelf
Republic Act No. 12065 (Philippine Archipelagic Sea Lanes Act of 2024) — designates archipelagic sea lanes and air routes for unobstructed transit; implements UNCLOS Part IV provisions on archipelagic states
Republic Act No. 9522 (Philippine Baselines Law of 2009) — defined the baselines from which the above maritime zones are measured; addressed the status of the Kalayaan Island Group and the Scarborough Shoal as "Régime of Islands"
United Nations Convention on the Law of the Sea (UNCLOS, 1982) — the Philippines signed in 1982, ratified in 1984; provides the international legal framework for maritime zone definitions and dispute resolution
2016 Arbitral Award (PCA Case No. 2013-19, The Republic of the Philippines v. The People's Republic of China) — the Permanent Court of Arbitration tribunal ruled on the scope of the Philippines' and China's maritime entitlements and the legality of China's conduct; the award is final and binding under UNCLOS Annex VII
Administrative Order No. 29, s. 2012 — formally named the waters within the Philippines' EEZ in the South China Sea as the "West Philippine Sea"

What RA 12064 (Maritime Zones Act) does

Signed into law by President Marcos in November 2024, RA 12064 is the first Philippine statute to codify the country's maritime zones as defined by UNCLOS directly in domestic legislation. Before this law, Philippine maritime zone boundaries were defined by executive act and the 2009 Baselines Law (RA 9522) without being formally declared in a comprehensive statute. RA 12064 declares the specific zones: a territorial sea of 12 nautical miles within which the Philippines exercises full sovereignty (subject to the right of innocent passage); a contiguous zone of 24 nautical miles within which the Philippines may enforce laws on customs, fiscal, immigration, and sanitary matters; an Exclusive Economic Zone of 200 nautical miles within which the Philippines holds sovereign rights — not full sovereignty, but exclusive rights to explore, exploit, conserve, and manage natural resources (fish, oil, gas, minerals); and a continental shelf extending to 200 nautical miles (or beyond, where the natural prolongation of the land territory permits) within which the Philippines holds sovereign rights over seabed and sub-seabed resources.

Sovereignty versus sovereign rights: the critical distinction

The most important legal distinction in West Philippine Sea discussions is the difference between full sovereignty and sovereign rights. The Philippines exercises full sovereignty over its territory — the land islands and the 12-nautical-mile territorial sea. Within the territorial sea, foreign vessels must comply with Philippine law and may only pass through under the right of "innocent passage" (UNCLOS Article 17). In the EEZ (200 nautical miles), the Philippines does not exercise full sovereignty; it holds functional "sovereign rights" — exclusive authority over economic activities such as fishing, oil and gas extraction, and scientific research. Foreign vessels may navigate freely through the EEZ, but they may not fish or extract resources without Philippine permission. Chinese fishing and supply vessels operating in Philippine EEZ waters are therefore violating Philippine rights even though the Philippines does not claim those waters as sovereign territory in the same sense as the territorial sea.

The 2016 Arbitral Award and its legal status

The 2016 Arbitral Award is the most significant legal ruling on the South China Sea. The Tribunal, constituted under Annex VII of UNCLOS, ruled that China's "nine-dash line" claim — which overlaps extensively with the Philippine EEZ — has no basis under international law. The Tribunal ruled that Scarborough Shoal (Bajo de Masinloc/Huangyan Island) is a rock under UNCLOS Article 121(3), entitling China to a territorial sea of only 12 nautical miles around it but no EEZ. It also ruled that China had violated UNCLOS by interfering with Philippine fishing and resource extraction in the Philippine EEZ, destroying coral reefs, and failing to prevent Chinese fishermen from harvesting endangered species at Scarborough Shoal. China does not recognize the award or the Tribunal's jurisdiction and has refused to comply. The Philippines consistently invokes the award in diplomatic statements as an authoritative legal ruling in its favor.

What RA 12065 (Archipelagic Sea Lanes Act) does

RA 12065, also signed in 2024, implements UNCLOS Article 53's provision allowing archipelagic states to designate sea lanes and air routes through their archipelagic waters. The Philippines — as an archipelagic state under UNCLOS — is entitled to normal archipelagic passage through these designated routes, giving foreign ships and aircraft a right of unobstructed transit through the Philippine archipelago without needing to seek permission for each transit. The law empowers the NAMRIA (National Mapping and Resource Information Authority) and the PCG (Philippine Coast Guard) to publish these lane designations in official notices to mariners.

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