Archipelagic Waters

Concept International Law Preferred

Waters enclosed by an archipelagic State's baselines, over which it has sovereignty regardless of depth or distance.

Independent referenceNot an official or legal definition
Sources citedSee the sources at the end of this page
Status Under reviewLast updated 11 October 2026
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Definition

In plain language

These are the seas between the islands of an island nation. The country has sovereignty over them, but foreign ships keep certain rights of passage.

Academic definition

UNCLOS Article 49(1) provides that the sovereignty of an archipelagic State extends to the waters enclosed by its baselines, described as archipelagic waters, regardless of their depth or distance from the coast, and also to the airspace above and the seabed beneath. This sovereignty is subject to the regime of Part IV, including the right of innocent passage (Article 52) and the right of archipelagic sea lanes passage in designated sea lanes and air routes (Article 53). Existing agreements, traditional fishing rights and submarine cables of other States must also be respected (Article 51).

Classification

Term type
Concept
Category
International Law
Subject field
Law of the Sea
Subfield
Archipelagic Regime
Difficulty level
Advanced
Grammatical category
noun phrase

Language variants

Alternative terms
  • waters enclosed by archipelagic baselines
Non-preferred terms
  • not_applicable
Abbreviations
  • not_applicable
Acronyms
  • not_applicable
Native terms
  • not_applicable
Transliteration
not_applicable
Pronunciation
not_applicable

Context

Legal effect: Binding

Scope

Covers the waters inside archipelagic baselines; the status of the State is separate, and the territorial sea measured outside the baselines is a different zone.

Legal context

UNCLOS Articles 49 to 53: sovereignty (49), delimitation of internal waters in bays and ports (50), existing agreements and traditional fishing rights (51), innocent passage (52) and sea lanes passage (53). Where no sea lanes are designated, the right of archipelagic sea lanes passage may be exercised through routes normally used for international navigation.

Diplomatic context

Disputes arise over designation of sea lanes, which maritime powers want broad, and over whether archipelagic States can restrict military transit.

Institutional context

National authorities propose sea lanes to the International Maritime Organization, which adopts them if they conform to international rules.

Historical context

Before UNCLOS in 1982 the waters between island groups were generally treated as high seas or territorial sea, depending on distances; the 1982 Convention created the archipelagic waters category.

Why it matters

It decides whether an island nation can regulate fishing, shipping and security across its inter-island seas or only in narrow coastal belts.

Usage

Register: Legal

Usage note

Use 'archipelagic waters' in the plural; do not use as a synonym for the territorial sea or internal waters.

Example

Foreign warships transited the archipelagic waters along a designated sea lane without seeking prior permission.

Example scenario

A tanker sails between two islands of State A. As the waters are archipelagic, State A has sovereignty, but the tanker may exercise archipelagic sea lanes passage in the designated corridor without prior notification.

Common misuse

Treating archipelagic waters as internal waters with no passage rights; foreign ships keep innocent passage and archipelagic sea lanes passage.

Not to be confused with

  • Internal waters
  • Territorial sea
  • Archipelagic State status

Sources

  1. United Nations Convention on the Law of the Sea (1982), United Nations, Articles 49-53. un.org
  2. Official definition. not_found_in_source
  3. Treaty reference. un.org
  4. Churchill and Lowe, The Law of the Sea. not_found_in_source
  5. not_found_in_source. not_found_in_source

Source type: Treaty. Source reliability: Primary.

This entry is an independent reference definition, not an official or legally binding text. Where an official definition exists, it is linked above and is authoritative. Read our methodology.

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