Law and Philippine territorial waters

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In order for an entity to be considered a State it must have four components: people, territory, government, and the capacity to enter into relations with other States. That’s from the 1st article of the 1933 Montevideo Convention, considered embodying international law on the creation of States.

With regard to territory, it all begins with land. There cannot be a State located purely on water. For land to be acquired, international law determined the following to be the permitted modes of acquisition: occupation, prescription, conquest (nowadays that would mean as a result of armed conflict conducted in self-defense), cession, and accretion.

The moment ownership of land is settled, the fluvial and maritime, as well as aerial territories, naturally follow. For seas, the 1982 UN Convention on the Law of the Sea (UNCLOS) — of which the Philippines has been a party since May 8, 1984 — substantially embodies much of international law on the nature and composition of maritime domains.

First, the baselines: the low water mark on the beach following the curvature of the coast. From that “normal baseline” count 12 nautical miles. A nautical mile is equivalent to 1.852 kilometers or 1.1508 miles. Those 12 nautical miles constitute the country’s territorial sea. Anything within the 12 nautical mile area is Philippine territory, which means that anyone or anything within that zone is subject to Philippine laws. Philippine territory ends past the 12th nautical mile.

However, international law (particularly as provided for under the 1982 UNCLOS) provided certain recognitions to an archipelagic country like the Philippines. If the normal baseline method is solely used it will result in swathes of “open seas” between our islands. This could lead to breaches of security and other violations of Philippine rights. Hence, the archipelagic doctrine: make imaginary lines from the outermost tips of the islands, each line not exceeding 100 nautical miles (subject to certain exceptions).


Those imaginary lines now constitute the “straight baselines.” Effectively, the 7,641 islands form a single unit. The waters inward of the straight baseline, towards the direction of the islands, are called either “internal waters” or “archipelagic waters.” The waters outward from the straight baseline, to the extent of 12 nautical miles, form the territorial seas.

International law and the 1982 UNCLOS also provided additional maritime spaces, which States can exercise jurisdiction over for certain specific purposes. Twelve nautical miles from the edge of the territorial sea is the area known as the “contiguous zone.” Within it, Philippine laws are applied and enforced with regard to fiscal, immigration, sanitary, and customs matters.

Furthermore, within 200 nautical miles from the baseline is the “exclusive economic zone” or “patrimonial sea.” And then finally, within a maximum distance of 350 nautical miles from the baseline is an area that lies under the ocean, a drop-off point called the shelf break, which descends toward the deep ocean floor. That is the continental shelf. The Philippine Rise is an example. Any resource (mineral, oil, gas, plant, fisheries) found in those two areas belong exclusively to the Philippines.

Ownership or jurisdiction over the above-mentioned areas, with the concomitant rights, privileges, and power that the Philippines can exercise, all flow from the fact of legal ownership over our lands. Put another way: from the time the lands were effectively acquired pursuant to any of the aforesaid five modes, the sea areas described here automatically form part of the territory of the Philippines or over which the Philippines can exercise certain jurisdiction, generally without need of further action by the Philippines.

The Philippines, nevertheless, has taken extra steps to announce to the world what our territories are by declaring the same repeatedly and consistently through our constitutions, treaties (e.g., with Spain, the US, Great Britain, and others), laws (e.g., PD 1596, PD 1599 [claiming the EEZ], PD 370 [claiming the continental shelf], RA 9522 [previously RA 3046, as amended by RA 5446], AO 29/s.2012), notifications to relevant international organizations (e.g., the UN and the Commission on the Limits of the Continental Shelf), and finally by adhering to the international law doctrine of incorporation.

Maps delineating exact coordinates are not necessary. Admittedly, they can be employed for evidentiary purposes but, nevertheless, international jurisprudence has been quite wary of their actual value. Ultimately, territories are acquired by operation of international law. As the Deutsche Continental Gas-Gesellschaft vs. Polish State case points out: no statutory or exact delineation of the territory is needed and even if the territories claimed are disputed, so long as the territory has been claimed with sufficient consistency and acquired through the modes provided for under international law, then that is the State’s territory.

In fine, both in terms of domestic and international law, Philippine ownership or jurisdiction over the territories it possesses or claims are conclusive. And that goes definitely for the Kalayaan Islands and Bajo de Masinloc, the seas surrounding them, the Philippine Rise, and the rest of the West Philippine Sea.


Jemy Gatdula is a Senior Fellow of the Philippine Council for Foreign Relations and a Philippine Judicial Academy law lecturer for constitutional philosophy and jurisprudence.

Twitter @jemygatdula