Law of the Sea

Function of the Law of the Sea

The law of the sea allocates authority over maritime spaces by measuring zones from baselines and by attaching different degrees of coastal-state power to each zone. Its central method is spatial: the nearer the waters are to land territory, the stronger the coastal State's sovereignty; the farther the waters are from the coast, the more the regime shifts toward sovereign rights, limited jurisdiction, and shared freedoms.

For the Philippines, the law of the sea operates together with the constitutional definition of national territory, the archipelagic character of the State, the Philippine Baselines Law, the Philippine Maritime Zones Act, and treaty obligations under the United Nations Convention on the Law of the Sea. Domestic law identifies the zones the Philippines claims and administers, while international law determines the limits, legal character, and opposability of those claims against other States.

The distinction between sovereignty, sovereign rights, and jurisdiction is basic. Sovereignty is comprehensive authority similar to authority over land territory, subject to treaty-based navigation rights. Sovereign rights are functional and exclusive rights over specified resources or activities. Jurisdiction is regulatory or enforcement competence over matters such as customs, immigration, marine scientific research, artificial islands, and protection of the marine environment.

Maritime rights are generated by land. A State must first have sovereignty over land territory or a maritime feature capable of generating an entitlement before it can claim a territorial sea, exclusive economic zone, or continental shelf from that feature. The law of the sea does not itself decide sovereignty over land territory; it determines the maritime consequences of land sovereignty.

Baselines and Philippine Maritime Space

A baseline is the line from which the breadth of maritime zones is measured. The ordinary baseline is the low-water line along the coast, but special rules allow straight baselines and archipelagic baselines when geography justifies their use. Because the Philippines is an archipelagic State, it uses archipelagic baselines joining appropriate outermost points of the outermost islands and drying reefs of the archipelago.

Waters enclosed by archipelagic baselines are archipelagic waters. The Philippines has sovereignty over these waters, their airspace, seabed, subsoil, and resources, but that sovereignty is exercised subject to rights recognized by the law of the sea, including innocent passage and archipelagic sea lanes passage.

The constitutional description of waters around, between, and connecting the islands as part of Philippine national territory does not eliminate the treaty obligations attached to archipelagic waters. The better view is that the Philippines retains sovereignty over the archipelagic waters, but foreign ships and aircraft may enjoy treaty-based passage rights where the law of the sea grants them.

The Baselines Law and later maritime zones legislation align Philippine domestic law with the maritime-zone structure of the law of the sea. They do not by themselves settle sovereignty over every disputed feature, and they do not abandon territorial claims merely because certain areas are described under the regime applicable to islands or other maritime features.

Kalayaan Island Group and Bajo de Masinloc are treated in Philippine law in a manner distinct from the main archipelagic baselines because their legal treatment depends on the separate question of sovereignty over the features and the maritime zones that each feature may generate under international law. This distinction preserves the difference between territorial claims over land features and zone claims measured from accepted baselines.

Maritime Zones

Each maritime zone carries a different bundle of rights. The controlling inquiry is not merely distance from the coast, but the legal character of the waters, seabed, subsoil, airspace, and resources involved.

Internal Waters

Internal waters are waters on the landward side of the baseline. In these waters, the coastal State generally may exclude foreign vessels, prescribe entry conditions, regulate activities, and enforce its laws as it does on land.

Where the use of straight baselines encloses as internal waters areas that were not previously considered internal, international law may preserve a right of innocent passage. This qualification prevents a change in baselines from extinguishing established navigational interests without legal basis.

Archipelagic Waters

Archipelagic waters are neither ordinary internal waters nor high seas. The archipelagic State has sovereignty over them, but the regime is balanced by navigation and overflight rights necessary for international communication.

The Philippines may regulate fisheries, environmental protection, customs, immigration, safety, and security within archipelagic waters. Regulation must remain consistent with treaty-based passage rights, existing lawful uses, and the obligation not to hamper passage beyond what international law permits.

Traditional fishing rights and existing submarine cables may receive protection in archipelagic waters where international law recognizes them. Such rights are not a general license to exploit resources, and they depend on the specific legal basis by which they are claimed.

Territorial Sea

The territorial sea is part of the coastal State's sovereign space. Sovereignty extends to the airspace above it and to its seabed and subsoil, but foreign ships enjoy the right of innocent passage.

Passage means navigation through the territorial sea for traversing it without entering internal waters, for proceeding to or from internal waters, or for calling at a port or roadstead. Passage must be continuous and expeditious, although stopping and anchoring are allowed when incidental to ordinary navigation, required by distress, or necessary to assist persons, ships, or aircraft in danger.

Passage is innocent only so long as it is not prejudicial to the peace, good order, or security of the coastal State. Activities inconsistent with innocence include threat or use of force, weapons exercises, intelligence gathering, serious propaganda acts, launching or taking on aircraft or military devices, unlawful loading or unloading of persons or goods, willful serious pollution, fishing, research or survey activities, interference with communications, and activities not having a direct bearing on passage.

The coastal State may adopt laws on navigation safety, conservation, fisheries, pollution control, customs, fiscal, immigration, sanitary matters, and protection of cables and pipelines. It may not impose requirements that effectively deny or impair innocent passage, and it may not discriminate in form or fact against ships of any State.

A foreign warship or government ship operated for non-commercial purposes that violates coastal-state laws on passage and disregards a request for compliance may be required to leave the territorial sea immediately. The flag State remains internationally responsible for loss or damage caused by such non-compliance.

Contiguous Zone

The contiguous zone is not a zone of sovereignty. It is a preventive and enforcement belt that allows the coastal State to protect specific interests connected with its territory and territorial sea.

The four protected categories are customs, fiscal, immigration, and sanitary laws. Enforcement in the contiguous zone must be tied to preventing or punishing infringement of those laws within the coastal State's territory or territorial sea, not to exercising general police power over all conduct at sea.

Exclusive Economic Zone

The exclusive economic zone gives the coastal State sovereign rights to explore, exploit, conserve, and manage living and non-living natural resources of the waters, seabed, and subsoil. It also gives jurisdiction over artificial islands, installations and structures, marine scientific research, and protection and preservation of the marine environment.

Coastal-state rights in the exclusive economic zone are exclusive for resource purposes. If the coastal State does not explore or exploit the resources, no other State may do so without its consent.

The exclusive economic zone is not territorial sea. Other States retain the freedoms of navigation and overflight, the laying of submarine cables and pipelines, and other internationally lawful uses of the sea related to those freedoms.

The governing standard in the exclusive economic zone is due regard. The coastal State must have due regard to the rights and duties of other States, and other States must have due regard to the coastal State's resource rights and regulatory jurisdiction.

For fisheries, the coastal State must promote conservation and optimum utilization of living resources. It may determine allowable catch, regulate fishing by licensing and conditions, protect species, and enforce conservation measures consistent with international law.

Continental Shelf

The continental shelf concerns the seabed and subsoil, not the water column as such. The coastal State has sovereign rights over the continental shelf for exploring and exploiting natural resources, including mineral resources and sedentary species.

Continental shelf rights are inherent and do not depend on occupation, proclamation, or actual exploitation. No other State may explore or exploit the shelf without the coastal State's consent.

The legal status of the waters above the continental shelf remains separate. A continental shelf beyond 200 nautical miles does not create an exclusive economic zone beyond 200 nautical miles, and it does not diminish the navigation and overflight freedoms of other States in the waters above.

The Philippine Rise illustrates the distinction between territory and maritime entitlement. The Philippines has sovereign rights over the continental shelf resources of the area where recognized under the law of the sea, but the seabed entitlement is not the same as land territory.

High Seas and the Area

The high seas are open to all States, whether coastal or landlocked. Freedoms include navigation, overflight, laying submarine cables and pipelines, constructing lawful artificial islands and installations, fishing, and marine scientific research.

High seas freedoms must be exercised with due regard for the interests of other States and for rights under the international seabed regime. No State may validly subject any part of the high seas to its sovereignty.

Ships on the high seas are generally subject to the exclusive jurisdiction of their flag State. Exceptions are narrowly recognized, including piracy, slave transport, unauthorized broadcasting, stateless vessels, valid right of visit, and hot pursuit begun lawfully from a zone where the pursuing State had enforcement jurisdiction.

The Area is the seabed and ocean floor beyond national jurisdiction. Its mineral resources are treated as the common heritage of mankind and are administered through the international seabed regime rather than unilateral national appropriation.

Navigation Regimes

Navigation rights differ by zone. A vessel's rights in internal waters, archipelagic waters, territorial sea, straits, exclusive economic zone, and high seas cannot be treated as identical.

Innocent passage applies to foreign ships in the territorial sea and, subject to the archipelagic regime, in archipelagic waters. It is a right of ship passage, not a general right of overflight, military exercise, fishing, survey, or resource use.

Transit passage applies in straits used for international navigation between one part of the high seas or an exclusive economic zone and another. It is broader than innocent passage because it includes continuous and expeditious transit in the normal modes of operation of ships and aircraft, and it may not be suspended.

Archipelagic sea lanes passage allows foreign ships and aircraft to pass through or over archipelagic waters and the adjacent territorial sea along designated sea lanes or routes normally used for international navigation. It must be continuous, expeditious, and unobstructed, and it is limited to transit from one part of the high seas or exclusive economic zone to another.

The Philippine Archipelagic Sea Lanes Act gives domestic form to the archipelagic sea lanes regime. Its significance is that Philippine sovereignty over archipelagic waters coexists with a structured passage regime for international navigation and overflight.

Freedom of navigation is strongest in the high seas and remains protected in the exclusive economic zone. It does not authorize foreign vessels to exploit resources, conduct unlawful marine scientific research, or disregard valid coastal-state regulations within zones where the coastal State has recognized jurisdiction.

Maritime Features and Entitlements

The maritime entitlement of a feature depends on its natural condition and legal classification. A State cannot expand maritime zones by building structures on a feature that has no natural entitlement.

An island is a naturally formed area of land, surrounded by water, and above water at high tide. A full island can generate a territorial sea, contiguous zone, exclusive economic zone, and continental shelf.

A rock that cannot sustain human habitation or economic life of its own generates only a territorial sea and contiguous zone. It does not generate an exclusive economic zone or continental shelf.

A low-tide elevation is above water at low tide but submerged at high tide. It does not generate its own maritime zones unless it is located within the territorial sea of the mainland or an island and is used as a baseline point under applicable rules.

An artificial island, installation, or structure does not possess the status of an island. It has no territorial sea of its own, although the coastal State may establish safety zones around it where allowed by international law.

Historic claims to maritime control cannot override the zone system where they claim resources or jurisdiction beyond entitlements recognized by the law of the sea. Historic title and historic rights are exceptional concepts and must be distinguished from broad assertions of control over semi-enclosed seas or resource-rich waters.

Resources, Research, and Environmental Protection

The law of the sea allocates resource control according to both place and resource type. Living resources in the exclusive economic zone, mineral resources of the continental shelf, sedentary species, and seabed minerals beyond national jurisdiction are governed by different regimes.

In the exclusive economic zone, the Philippines may regulate fishing, determine allowable catch, require licenses, prescribe gear and vessel conditions, protect marine species, and enforce conservation rules. Foreign access to surplus living resources depends on coastal-state authorization and applicable agreements.

On the continental shelf, the Philippines has exclusive sovereign rights over minerals and other non-living resources of the seabed and subsoil. These rights exist even if the waters above remain subject to navigation freedoms or, beyond 200 nautical miles, high seas freedoms.

Marine scientific research in the territorial sea requires coastal-state consent because it occurs in sovereign waters. In the exclusive economic zone and on the continental shelf, coastal-state consent is also required because research may affect resource rights, environmental duties, and sovereign-resource jurisdiction.

Protection and preservation of the marine environment is both a coastal-state interest and a treaty obligation. The Philippines may adopt and enforce measures against vessel-source pollution, dumping, seabed activities, and pollution from installations, but enforcement must correspond to the zone and the internationally recognized jurisdiction available there.

Conservation duties limit unilateral exploitation. A State with resource rights must manage living resources rationally, prevent serious environmental harm, cooperate where stocks migrate or straddle maritime boundaries, and respect duties owed to other States and the international community.

Enforcement at Sea

Maritime enforcement depends on the zone, the vessel, the activity, and the legal interest protected. A measure valid in internal waters may be excessive in the exclusive economic zone, and a measure valid against a private fishing vessel may be unavailable against a foreign warship.

In internal waters and ports, the coastal State has its strongest enforcement authority. It may apply port conditions, customs and immigration rules, safety measures, and criminal laws, subject to immunities and applicable treaty obligations.

In the territorial sea, enforcement may protect sovereignty and regulate passage, but it must respect innocent passage. Criminal jurisdiction over a foreign ship passing through the territorial sea is generally exercised with restraint, especially where the offense does not affect the coastal State, disturb the peace of the territorial sea, involve illicit traffic, or require assistance from local authorities.

In the contiguous zone, enforcement is limited to customs, fiscal, immigration, and sanitary interests connected with the territory or territorial sea. It is not a general security zone and cannot be used to convert the exclusive economic zone into territorial waters.

In the exclusive economic zone, enforcement is strongest for fisheries, resource activities, artificial islands, marine scientific research, and environmental protection. Arrest, inspection, and penalties must conform to international limits, including prompt release obligations where applicable.

Hot pursuit permits a coastal State to pursue a foreign ship onto the high seas when there is good reason to believe the ship violated laws in a zone where the coastal State had enforcement jurisdiction. Pursuit must begin while the foreign ship or one of its boats is within the relevant zone, must be continuous, and ends when the ship enters the territorial sea of its own State or a third State.

Warships and other government ships operated for non-commercial service enjoy sovereign immunity. The usual remedy for non-compliance is a demand that the vessel leave, followed by diplomatic and international responsibility measures rather than ordinary coercive enforcement against the vessel.

Maritime Disputes and Settlement

Maritime disputes commonly involve different legal questions that must be separated. A dispute over sovereignty over an island is different from a dispute over the maritime entitlements of that island, and both are different from delimitation of overlapping zones between opposite or adjacent coasts.

When exclusive economic zones or continental shelves overlap, States must reach an agreement achieving an equitable solution. Pending final agreement, they should make provisional arrangements of a practical nature and should not jeopardize or hamper the reaching of a final agreement.

Delimitation of the territorial sea ordinarily uses an equidistance approach unless historic title or special circumstances require a different line. Delimitation of the exclusive economic zone and continental shelf focuses on equitable solution, commonly considering relevant coasts, proportionality, and circumstances affecting fairness.

Compulsory dispute settlement under the law of the sea may proceed before the International Tribunal for the Law of the Sea, the International Court of Justice, an arbitral tribunal, or a special arbitral tribunal, depending on State declarations and the nature of the dispute. Where States have not chosen the same forum, arbitration is commonly the default mechanism.

Compulsory procedures have limits. Certain disputes involving sea boundary delimitation, historic bays or titles, military activities, law-enforcement activities in fisheries or marine scientific research, and matters before the United Nations Security Council may be excluded or subject to special treatment.

An international tribunal applying the law of the sea may decide the interpretation or application of maritime-zone rules without deciding sovereignty over land territory. It may determine whether a feature is an island, rock, low-tide elevation, or submerged feature for purposes of maritime entitlements, but it cannot award sovereignty over the feature unless it has jurisdiction over that separate issue.

In the West Philippine Sea context, the legally important distinctions are that maritime zones must be measured from land features recognized by law, historic-resource assertions cannot exceed the convention-based zone system, and artificial construction cannot transform a non-entitled feature into one capable of generating extensive maritime zones.

The legal effect of a binding maritime award is distinct from physical control at sea. An award may settle rights and obligations between parties under international law, but compliance, enforcement, diplomatic action, and operational protection of maritime rights remain separate questions of State policy and international responsibility.