Concept and Constitutional Basis
The archipelagic doctrine treats an archipelago as one integrated territorial unit, not as separate islands divided by intervening seas. Its central idea is that the waters around, between, and connecting the islands are juridically linked to the land territory because the islands and waters form a single geographical, economic, political, and historical whole.
For the Philippines, the doctrine is embedded in the constitutional description of national territory. The national territory includes the Philippine archipelago, with all the islands and waters embraced in it, and all other territories over which the Philippines has sovereignty or jurisdiction. It includes the terrestrial, fluvial, and aerial domains, including the territorial sea, seabed, subsoil, insular shelves, and other submarine areas.
The Constitution states the archipelagic rule in its most compact form: waters around, between, and connecting the islands of the archipelago, regardless of breadth and dimensions, form part of the internal waters of the Philippines.
This constitutional formulation expresses the domestic law position that inter-island waters are not foreign seas separating the islands. The Philippines is not a collection of isolated land masses; it is a unitary archipelagic State whose land, waters, and airspace are treated as components of one national territory.
In international law, the same basic concept is implemented through the regime of archipelagic States under the law of the sea. International law uses the term archipelagic waters for waters enclosed by valid archipelagic baselines, while Philippine constitutional language describes the waters around, between, and connecting the islands as internal waters. The two formulations must be read together: the Constitution states the national territorial concept, while international law supplies the rules by which that concept is asserted against other States.
Archipelagic State and Archipelago
An archipelagic State is a State constituted wholly by one or more archipelagos and may include other islands. The Philippines qualifies because its main territory consists of a group of islands and interconnecting waters so closely related that they form an intrinsic geographical, economic, and political entity.
An archipelago is not merely a random cluster of islands. The islands, waters, and natural features must be so interrelated that the sea is part of the unity of the State, rather than a barrier separating unrelated territories. Historical treatment may strengthen this unity when the islands and waters have long been governed, defended, used, and identified as one political community.
The doctrine is especially important for the Philippines because its governmental administration, national defense, fisheries, inter-island commerce, transportation, marine environment, and internal security all depend on treating inter-island waters as part of the national domain.
Archipelagic Baselines
Archipelagic baselines are straight lines joining the outermost points of the outermost islands and drying reefs of an archipelagic State. They enclose the main archipelago and serve as the starting lines from which the breadth of the territorial sea, contiguous zone, exclusive economic zone, and continental shelf is measured.
Baselines do not create land territory. They are legal measuring lines for maritime zones. A baseline statute therefore does not, by itself, acquire territory, cede territory, or determine sovereignty over disputed land features. It identifies the points from which maritime entitlements are measured consistently with international law.
Republic Act No. 9522 adjusted the Philippine baselines to conform to the archipelagic baselines system. The adjustment preserved the constitutional concept of national territory while making the measurement of maritime zones compatible with the law of the sea. Treating a feature outside the main archipelagic baseline as subject to the regime of islands does not abandon the Philippine claim to that feature; it simply means its maritime zones are measured under the rules applicable to islands.
Basic Requirements for Valid Archipelagic Baselines
- Outer perimeter: The baselines must join the outermost points of the outermost islands and drying reefs of the archipelago.
- Main islands included: The baselines must enclose the main islands and an area in which the ratio of water to land falls within the limits recognized by international law.
- General configuration: The lines must follow the general shape of the archipelago and must not depart appreciably from it.
- Line length: The length of the baseline segments must comply with the maximum lengths allowed for archipelagic baselines, subject to the limited allowance for longer segments.
- Low-tide elevations: Baselines generally may not be drawn to or from low-tide elevations unless the accepted conditions for their use are present.
- Neighboring States: Baselines may not be drawn in a manner that cuts off another State's territorial sea from the high seas or an exclusive economic zone.
Baseline Methods Distinguished
| Method | Use | Legal Effect |
|---|---|---|
| Normal baseline | Low-water line along the coast of an island or mainland coast | Ordinary starting line for measuring maritime zones |
| Straight baseline | Deeply indented coasts or coasts fringed by islands | Connects appropriate coastal points without converting a coastal State into an archipelagic State |
| Archipelagic baseline | Archipelagic States such as the Philippines | Encloses the archipelago as a unit and creates archipelagic waters inside the lines |
Waters Inside the Baselines
Waters enclosed by archipelagic baselines are archipelagic waters under international law. The archipelagic State has sovereignty over these waters, the airspace above them, their seabed and subsoil, and their resources. This sovereignty is real sovereignty, but it is exercised subject to the navigation and communication rights recognized by international law.
Philippine constitutional law describes the waters around, between, and connecting the islands as internal waters. International law, however, distinguishes archipelagic waters from internal waters because foreign vessels and aircraft may have passage rights through archipelagic waters. The practical reconciliation is that the Philippines asserts territorial unity over the waters, while accepting international passage rights that qualify the exercise of sovereignty.
Some waters within the archipelagic system may still be internal waters in the strict international sense, such as waters landward of valid closing lines across bays, river mouths, or ports. Internal waters are subject to the most complete form of coastal State authority, while archipelagic waters carry special passage rights.
Legal Character of Relevant Waters
| Area | Character | Principal Consequence |
|---|---|---|
| Internal waters in the strict sense | Waters landward of normal baselines or valid closing lines | Foreign vessels generally have no passage right without consent, subject to recognized exceptions |
| Archipelagic waters | Waters enclosed by archipelagic baselines | Philippine sovereignty applies, subject to innocent passage and archipelagic sea lanes passage |
| Territorial sea | Belt measured outward from the baselines | Philippine sovereignty applies, subject principally to innocent passage |
| Exclusive economic zone | Maritime zone measured outward from the baselines | The Philippines has sovereign rights over resources and specified jurisdiction, not full territorial sovereignty |
| Continental shelf | Seabed and subsoil entitlement measured under international law | The Philippines has sovereign rights over exploration and exploitation of seabed resources |
Effect on National Territory
The archipelagic doctrine protects the territorial integrity of the Philippines by preventing the waters between the islands from being treated as high seas or foreign waters. Without the doctrine, wide bodies of water separating islands could weaken the unity of the State and expose inter-island routes to claims of unrestricted foreign use.
The doctrine supports sovereignty over the archipelago, but it does not convert every maritime entitlement into land territory. Sovereignty over land territory, internal waters, archipelagic waters, the territorial sea, and airspace must be distinguished from sovereign rights and jurisdiction in zones such as the exclusive economic zone and continental shelf.
Sovereignty is the full legal authority of the State over territory, subject to international obligations. Sovereign rights are functional rights for specified purposes, especially the exploration, exploitation, conservation, and management of natural resources. Jurisdiction refers to authority over particular matters, such as marine scientific research, environmental protection, customs, fiscal, immigration, sanitary control, and artificial islands or installations.
The Constitution includes territories over which the Philippines has sovereignty or jurisdiction because national territory is not limited to the main island group. The phrase accommodates both full sovereign territory and maritime areas where international law gives the Philippines jurisdiction or sovereign rights without full territorial sovereignty.
Passage Through Archipelagic Waters
Foreign vessels may not treat archipelagic waters as high seas, but they are not always dependent on discretionary permission to pass. The law of the sea recognizes passage rights that balance the territorial unity of the archipelagic State with the international community's interest in navigation and overflight.
Innocent Passage
Innocent passage is navigation through the territorial sea or archipelagic waters that is continuous and expeditious, and that is not prejudicial to the peace, good order, or security of the coastal or archipelagic State. It covers passage for traversing the waters without entering internal waters, or for proceeding to or from internal waters or a port facility.
Passage is not innocent when a vessel engages in activities such as threats or use of force, weapons exercises, intelligence gathering, propaganda affecting defense or security, launching or taking aboard aircraft or military devices, loading or unloading contrary to customs or immigration laws, willful serious pollution, fishing, research or survey activities, interference with communication systems, or any other activity not having a direct bearing on passage.
The Philippines may regulate innocent passage through laws on navigation safety, traffic separation, conservation of living resources, fisheries, environmental protection, customs, fiscal matters, immigration, sanitation, and security. Regulation must be applied consistently with international law and must not be used to nullify the passage right.
Innocent passage may be temporarily suspended in specified areas of archipelagic waters when the suspension is essential for the protection of security and is applied without discrimination. Suspension must be exceptional because passage is a recognized legal right, not a mere courtesy.
Archipelagic Sea Lanes Passage
Archipelagic sea lanes passage is the exercise of navigation and overflight in the normal mode solely for continuous, expeditious, and unobstructed transit between one part of the high seas or exclusive economic zone and another part of the high seas or exclusive economic zone. It is broader than innocent passage because it includes aircraft overflight and permits ships and aircraft to proceed in their normal mode.
The archipelagic State may designate sea lanes and air routes suitable for continuous and expeditious passage. The designation must include all normal passage routes used for international navigation and overflight. If no sea lanes are validly designated, the right may be exercised through routes normally used for international navigation.
Archipelagic sea lanes passage may not be suspended. The Philippines may adopt laws relating to safety, traffic, pollution control, fishing, customs, immigration, and security in accordance with international law, but it may not hamper, deny, or impair the essence of the passage right.
Comparison of Passage Rights
| Point of Comparison | Innocent Passage | Archipelagic Sea Lanes Passage |
|---|---|---|
| Area | Territorial sea and archipelagic waters | Designated sea lanes and air routes, or normal international navigation routes if none are designated |
| Purpose | Continuous and expeditious passage that is not prejudicial to peace, good order, or security | Continuous, expeditious, and unobstructed transit between high seas or exclusive economic zone areas |
| Overflight | Not included | Included |
| Normal mode | Limited by rules applicable to innocent passage | Allowed, including normal navigational mode for ships and aircraft |
| Suspension | May be temporarily suspended in proper cases | May not be suspended |
Limitations on Philippine Authority in Archipelagic Waters
Archipelagic sovereignty is not absolute in the sense of being free from treaty and customary limitations. The Philippines must exercise authority over archipelagic waters consistently with the passage rights of foreign ships and aircraft, existing international agreements, and other obligations under the law of the sea.
The archipelagic State must respect existing agreements with other States and, in appropriate cases, traditional fishing rights and legitimate activities of immediately adjacent neighboring States in certain areas of archipelagic waters. Such rights depend on recognized legal bases and implementing arrangements; they are not a general license for foreign exploitation of Philippine marine resources.
The archipelagic State must also respect existing submarine cables laid by other States and must permit their maintenance or replacement upon proper notice. This obligation reflects the international importance of communication infrastructure while preserving the State's authority over activities in its waters.
Warships and government vessels operated for non-commercial service retain sovereign immunity, but they must comply with the laws and regulations of the archipelagic State relating to passage. If a warship disregards those rules and ignores a request for compliance, the Philippines may require it to leave the relevant waters immediately, and the flag State may incur responsibility for resulting loss or damage.
Regime of Islands and Philippine Features Outside the Main Baselines
The archipelagic doctrine governs the main Philippine archipelago, but not every Philippine-claimed feature must be enclosed within the main archipelagic baselines. Kalayaan Island Group and Bajo de Masinloc are treated by Philippine baseline legislation under the regime of islands, which means their maritime zones are determined according to the legal character of each feature.
An island is a naturally formed area of land, surrounded by water, and above water at high tide. An island capable of generating the full suite of maritime zones may have its own territorial sea, contiguous zone, exclusive economic zone, and continental shelf. A rock that cannot sustain human habitation or economic life of its own does not generate an exclusive economic zone or continental shelf. A low-tide elevation generally does not generate maritime zones of its own unless it is situated in a legally relevant position relative to a proper baseline.
Placing a feature under the regime of islands is a method of measuring maritime entitlements, not a statement that the feature is outside Philippine sovereignty. The question of sovereignty over land features is distinct from the question of what maritime zones those features can lawfully generate.
Relationship with Airspace, Seabed, and Resources
Philippine sovereignty over archipelagic waters extends to the airspace above them and to their bed, subsoil, and resources. Unauthorized foreign aircraft may not rely on innocent passage because innocent passage is a navigational right of ships. Aircraft may exercise overflight only where archipelagic sea lanes passage or another recognized legal basis applies.
The State's authority over the seabed and subsoil of archipelagic waters is part of territorial sovereignty. This is different from sovereign rights over the continental shelf, where the Philippines has exclusive rights for exploration and exploitation of seabed resources even though the water column above may not be Philippine territory.
Living and non-living resources in archipelagic waters are subject to Philippine sovereignty, conservation laws, environmental regulation, and enforcement jurisdiction. In the exclusive economic zone, the Philippines has sovereign rights over natural resources and jurisdiction over specified activities, but other States retain freedoms of navigation, overflight, and laying of submarine cables and pipelines consistent with international law.
Legal Consequences of the Doctrine
- The islands and interconnecting waters of the Philippine archipelago are treated as a single territorial unit.
- Waters enclosed by archipelagic baselines are not high seas and are not open to unrestricted foreign use.
- Philippine sovereignty extends to archipelagic waters, their airspace, seabed, subsoil, and resources, subject to international law.
- The breadth of maritime zones is measured from the archipelagic baselines, not from each island separately within the main archipelago.
- Baseline legislation measures maritime zones and does not by itself determine ownership of disputed land features.
- Foreign ships may enjoy innocent passage through archipelagic waters, subject to Philippine regulation and security interests.
- Ships and aircraft may enjoy archipelagic sea lanes passage for continuous, expeditious, and unobstructed transit through recognized routes.
- Archipelagic sea lanes passage cannot be suspended, while innocent passage may be suspended only in legally limited situations.
- Features outside the main archipelagic baselines may still be claimed by the Philippines and may generate maritime zones under the regime of islands.
- Sovereignty over territory must be distinguished from sovereign rights and jurisdiction in maritime zones beyond the territorial sea.
Integrated Application
The archipelagic doctrine gives legal expression to the physical and political reality that the Philippine sea connects rather than separates the islands. It justifies the use of archipelagic baselines, the treatment of enclosed waters as part of the national domain, and the extension of sovereignty to the airspace, seabed, subsoil, and resources associated with those waters.
At the same time, the doctrine operates within the law of the sea. The Philippines may protect territorial integrity, regulate navigation, conserve resources, and enforce its laws in archipelagic waters, but it must recognize innocent passage, archipelagic sea lanes passage, submarine cable obligations, and other accepted limitations on archipelagic sovereignty.
The controlling distinction is between territorial unity and maritime entitlement. The archipelagic doctrine unifies the islands and waters of the Philippine archipelago; baseline law measures the maritime zones flowing from that unity; and international law defines the rights of the Philippines and other States within each zone.