Articles 74, 83 and 121 of UNCLOS Read as Text: What the Law of the Sea Says on Delimitation and Islands

Why It Matters

UNCLOS says that maritime boundaries between States with opposite or adjacent coasts must be agreed 'on the basis of international law' so as to reach 'an equitable solution', and that islands generate the same zones as other land, except rocks that cannot sustain human habitation or economic life of their own. The Convention names the goal of delimitation, not a formula for reaching it. That gap between text and method is where the Eastern Mediterranean dispute lives.

This guide reads Articles 74, 83 and 121 as written, sets out how Greece, Cyprus and Türkiye each read them, and records the main Turkish legal 'ledger entries' (2004, 2020, 2025) for what they are. For the interpretive rules used throughout, see How Are Treaties Interpreted? Vienna Convention Articles 31–32 Applied to the Disputes in This Ledger.

Background

The Convention in one paragraph

The 1982 United Nations Convention on the Law of the Sea (UNCLOS) was adopted on 30 April 1982 by a recorded vote of 130 in favour, 4 against and 17 abstentions. Türkiye was among the four States voting against, together with the United States, Israel and Venezuela. It entered into force on 16 November 1994. Cyprus ratified in 1988 and Greece in 1995. Türkiye has not ratified or acceded. Article 309 prohibits reservations, which is one reason States with particular concerns about the text have stayed outside it.

Articles 74 and 83: the delimitation clauses

Article 74 governs the exclusive economic zone (EEZ) and Article 83 governs the continental shelf. Their wording is deliberately parallel. Article 74(1) reads:

The delimitation of the exclusive economic zone between States with opposite or adjacent coasts shall be effected by agreement on the basis of international law, as referred to in Article 38 of the Statute of the International Court of Justice, in order to achieve an equitable solution.

Article 83(1) uses the same sentence, substituting 'continental shelf'. Read as text, five features stand out:

1. Agreement comes first. Delimitation is 'effected by agreement'. No State may fix the boundary alone.
2. The benchmark is international law, not the Convention alone. The reference to Article 38 of the ICJ Statute points to treaties, custom, general principles and judicial decisions as sources.
3. The result, not the route, is prescribed. The required outcome is 'an equitable solution'. There is no mention of the median or equidistance line.
4. Failure triggers dispute settlement. Paragraph 2 sends States that cannot agree 'within a reasonable period of time' to the procedures in Part XV.
5. Interim cooperation is expected. Paragraph 3 asks States, pending agreement, to 'make every effort to enter into provisional arrangements of a practical nature' and not to 'jeopardize or hamper' a final agreement. Paragraph 4 says an agreement in force governs.

The contrast with the territorial sea is instructive. Article 15 provides a default for territorial sea boundaries: absent agreement, neither State may extend its territorial sea beyond the median line, unless historic title or other special circumstances justify a different line. Articles 74 and 83 contain no such default. This was the outcome of a long drafting contest at the Third UN Conference on the Law of the Sea between States favouring equidistance and States favouring equitable principles. The compromise formula leaves the method to the parties and, failing agreement, to a court or tribunal.

Article 121: the regime of islands

Article 121 is the only article in Part VIII. Its three paragraphs read, in substance:

• 121(1): An island is 'a naturally formed area of land, surrounded by water, which is above water at high tide'.
• 121(2): Except as provided in paragraph 3, the territorial sea, contiguous zone, EEZ and continental shelf of an island 'are determined in accordance with the provisions of this Convention applicable to other land territory'.
• 121(3): 'Rocks which cannot sustain human habitation or economic life of their own shall have no exclusive economic zone or continental shelf.'

Two textual points matter. First, paragraph 2 speaks of how zones are determined under the Convention's provisions for other land territory, and those provisions include Articles 74 and 83. Second, paragraph 3 removes only the EEZ and continental shelf from qualifying rocks; they keep a territorial sea. The Convention does not define 'rock', 'human habitation' or 'economic life of their own'. The 2016 arbitral award in the South China Sea case offered an interpretation of paragraph 3, but it binds only the parties to that case, and Türkiye is not party to either the Convention or that arbitration.

Entitlement versus delimitation

The text implies two analytically separate steps:

Article 76 is also relevant. Its paragraph 10 states that the shelf-definition provisions are without prejudice to delimitation between States with opposite or adjacent coasts. Under Article 76(8), the Commission on the Limits of the Continental Shelf (CLCS) makes recommendations to States parties on outer limits beyond 200 nautical miles. Annex II, Article 9, adds that the Commission's actions 'shall not prejudice matters relating to delimitation'. In short, no registration, notification or recommendation can by itself fix a boundary between neighbours.

The Ledger: Türkiye's recorded entries

Below are the principal Turkish and related entries, listed with what each records. Individual notifications can be checked on the UN Division for Ocean Affairs and the Law of the Sea (DOALOS) website and in Turkish Foreign Ministry publications.

A disciplined reading of the ledger distinguishes three things: a claim (what a State asserts), a record (where and when it lodged it), and a settlement (an agreement or judgment binding the parties). The entries above are claims and records. Only the 2011 and 2019 instruments are bilateral, and neither binds Greece or the Greek Cypriot administration.

Key Players & Positions

Greece

Greece is a party to UNCLOS and treats its provisions, including Article 121, as reflecting customary international law. In Athens' reading, Article 121(2) gives an inhabited island such as Kastellorizo (Megisti) the full range of zones, subject only to Article 121(3), which applies to uninhabitable rocks. Greek official statements hold that delimitation of the continental shelf and EEZ should proceed by equidistance or a median line as a starting point, and that this is the only maritime dispute with Türkiye that can be submitted to the International Court of Justice. Kastellorizo lies roughly 2 km (about 1.2 miles) off the Turkish mainland and over 500 km from the Greek mainland, a fact that shapes the whole argument. Greece also signed a partial EEZ delimitation agreement with Egypt on 6 August 2020, which Türkiye rejects.

The Republic of Cyprus (Greek Cypriot administration)

The Republic of Cyprus is a party to UNCLOS and has concluded EEZ delimitation agreements with Egypt (2003), Lebanon (2007, not ratified by Lebanon) and Israel (2010). It maintains that, as a State party, it is entitled to declare an EEZ and license hydrocarbon blocks around the island. The European Union has repeatedly stated in Council conclusions that UNCLOS reflects customary international law and has backed Cyprus and Greece on maritime rights. A map associated with a study prepared for the EU, usually called the 'Seville Map', shows a maximal Greek and Greek Cypriot projection in the Gulf of Antalya.

Türkiye and the Turkish Cypriots

Türkiye is not a party and argues that the Convention does not reflect a universally accepted balance on islands, semi-enclosed seas and delimitation. It maintains that the equitable principle in Articles 74 and 83 applies to it regardless, as general international law. The Turkish Republic of Northern Cyprus (TRNC) asserts that Turkish Cypriots, as co-founders of the 1960 Republic, hold equal rights over the island's offshore resources.

Third States and courts

Egypt, Libya, Lebanon and Israel have each concluded or contested delimitation arrangements in the region. The ICJ and ITLOS have, in other regions, applied Articles 74 and 83 through staged methods that begin with a provisional line and adjust it for relevant circumstances and proportionality. For a case-law treatment of how islands figure in that analysis, see The Worldlogue: Do Islands Generate a Full Continental Shelf? The Equity Principle and Türkiye's Longest Coastline. This guide keeps to the text.

Source Comparison

The same articles produce different headlines depending on the source. The table below compares framing, not facts.

When reading media coverage, check three points: whether the article quotes the Convention or only describes it; whether it distinguishes entitlement from delimitation; and whether it treats a registration as if it were a boundary. Primary sources include the UN treaty collection, DOALOS notifications, the MFA website, and the Presidency and the Directorate of Communications for Turkish positions. For this ledger's method, see the Editorial Principles.

Key Terms & Related Guides

• Continental shelf: the seabed and subsoil that extend from a coast; defined in Article 76 and delimited under Article 83.
• EEZ: a zone up to 200 nautical miles from baselines where the coastal State has sovereign rights over resources (Articles 55–57); delimited under Article 74.
• Equitable solution: the outcome required by Articles 74 and 83; the text does not define it, and its content has been developed through agreements and case law.
• Rock (Article 121(3)): a feature that cannot sustain human habitation or economic life of its own; entitled to a territorial sea but not an EEZ or continental shelf.
• Entitlement versus delimitation: the difference between what a coast or island can generate and where two States' overlapping zones meet.
• Blue Homeland (Mavi Vatan): the Turkish doctrine of maritime jurisdiction in the Black Sea, Aegean and Eastern Mediterranean, built on equity and coastal geography.
• CLCS: the Commission on the Limits of the Continental Shelf, which makes recommendations to States parties and does not delimit boundaries.

Related guides:

• The IOC-UNESCO Entry of 12 June 2025: What Türkiye's Marine Spatial Planning Registration Records, and What It Does Not
• The Türkiye–TRNC Continental Shelf Delimitation Agreement of 21 September 2011: A Reading of the Record
• How Are Treaties Interpreted? Vienna Convention Articles 31–32
• Treaty Ledger FAQ: Sources, Method and Perspective
• About Treaty Ledger: Mission, Method and Editorial Transparency
• Archive of Nations: The 2019 Türkiye–Libya Maritime Memorandum

Closing Ledger Note

The answer to 'what does UNCLOS actually say?' is short. Delimitation is by agreement on the basis of international law, aimed at an equitable solution; islands generally generate the same zones as land, while uninhabitable rocks do not generate an EEZ or shelf. Everything beyond that, including the method, the weight of islands and the forum, is argued from the text rather than stated in it.

Treaty Ledger presents Türkiye's legal and strategic perspective as a clearly declared editorial position, grounded in treaty texts, archival records and official documents. Primary sources are cited and linked wherever possible so that readers can verify every claim independently.