Eastern Mediterranean Watch: Who Claims What at Sea, and Where the 2025 IOC-UNESCO Registration Fits

Why It Matters

Eastern Mediterranean maritime claims explained in one sentence: several coastal states and the Turkish Cypriots project overlapping continental shelf and exclusive economic zone (EEZ) claims into one narrow basin, and none of the contested lines involving Türkiye has been settled by a binding treaty or court judgment. The stakes are offshore gas, fisheries, cable and pipeline routes, naval access and the legal status of islands.

The 2025 recording of Türkiye's Marine Spatial Planning with IOC-UNESCO added a new document to the file. Understanding what that registration is, and what it is not, requires first mapping who claims what.

Background

The geography and the legal frame

The Eastern Mediterranean is a semi-enclosed basin in which many coastlines face each other at less than 400 nautical miles, so full 200-nautical-mile EEZ claims necessarily collide. Delimitation is therefore the central legal question, not the existence of zones.

The main legal sources are:

• The 1982 UN Convention on the Law of the Sea (UNCLOS). Articles 74 and 83 require delimitation of the EEZ and continental shelf between opposite or adjacent coasts by agreement on the basis of international law, to reach an equitable solution. Article 121 governs islands. Greece, the Republic of Cyprus, Egypt and Lebanon are parties; Türkiye and Israel are not.
• Customary international law and case law. The ICJ's 1969 North Sea Continental Shelf judgments established equitable principles and natural prolongation. Later decisions, including the Libya/Malta case (1985), the Black Sea case between Romania and Ukraine (2009) and the Nicaragua v. Colombia case (2012), developed the method of a provisional line adjusted for relevant circumstances and checked for proportionality.
• Bilateral agreements. Because the basin is crowded, bilateral agreements, and objections to them by third parties, have been the main instruments of claim-making.

Türkiye's coast

According to the Turkish Ministry of Foreign Affairs, Türkiye has a coastline of about 870 km (roughly 540 miles) on the Eastern Mediterranean, the longest of any state on that sea. That figure underpins Ankara's argument about proportionality between coastal length and maritime area. Türkiye is not a party to UNCLOS and says it relies on customary law and equitable principles.

Chronology

Date	Event
1969	ICJ North Sea Continental Shelf judgments set out equitable principles in delimitation
1982	UNCLOS adopted; Türkiye voted against and has not become a party
8 June 1995	Grand National Assembly of Türkiye (TBMM) resolution on Aegean territorial waters, understood in Ankara as a red line against a 12-nautical-mile extension by Greece in the Aegean
2003	Republic of Cyprus–Egypt EEZ agreement; Ankara says it infringes Türkiye's continental shelf, overlapped by Cypriot Blocks 1, 4, 5, 6 and 7
2004	Türkiye begins lodging Eastern Mediterranean continental shelf coordinates with the United Nations
2007	Republic of Cyprus–Lebanon EEZ agreement signed (never ratified by Lebanon)
2009, 2012	Türkiye's state oil company TPAO granted exploration licences in the Eastern Mediterranean
2010	Republic of Cyprus–Israel EEZ agreement
19 September 2011	Republic of Cyprus begins unilateral offshore drilling
21 September 2011	Türkiye–TRNC Continental Shelf Delimitation Agreement signed
2019	EastMed Gas Forum founded in Cairo without Türkiye
27 November 2019	Türkiye–Libya maritime jurisdiction memorandum of understanding signed
18 March 2020	Türkiye registers the outer limits of its continental shelf with the UN
6 August 2020	Greece–Egypt partial EEZ agreement
27 October 2022	US-mediated Israel–Lebanon maritime arrangement
16 April 2025	Türkiye unveils its Marine Spatial Planning of the Republic of Türkiye
12 June 2025	Plan recorded with IOC-UNESCO
24 July 2025	Presidential Circular establishes an inter-agency coordination board under the Foreign Ministry

The drilling record

Türkiye says it has exercised its claimed rights through a national fleet: the drillships Fatih, Yavuz, Kanuni and Abdülhamid Han, and the seismic vessels Oruç Reis and Barbaros Hayreddin Paşa. Eight major wells are cited by Ankara in the Eastern Mediterranean: Alanya-1, Finike-1, Karpaz-1, Güzelyurt-1, Mağusa-1, Narlıkuyu-1, Lefkoşa-1 and Selçuklu-1. The Greek and Greek Cypriot side, and the European Union, have described some of this activity in areas claimed by Cyprus as unlawful, a characterization Ankara rejects.

Key Players & Positions

Each actor claims maritime zones from its own legal base, and each cites different instruments. The summary below attributes positions to the parties' own public stances.

Actor	Main claim	Legal instruments cited
Türkiye	Equity-based delimitation, full effect for its 870 km mainland coast, limited effect for small islands, equal rights for Turkish Cypriots	Customary law, ICJ case law, 2004 UN submissions, 2011 TRNC agreement, 2019 Libya MoU, 2020 UN registration, 2025 spatial plan
Greece	EEZ and continental shelf for islands, including Crete, Rhodes and Kastellorizo, as for other land territory	UNCLOS Articles 56, 76 and 121; Greece–Italy 2020 and Greece–Egypt 2020 agreements
Republic of Cyprus (Greek Cypriot administration)	EEZ licensed in numbered blocks and agreements with neighbours	2003 Egypt, 2007 Lebanon and 2010 Israel agreements; UNCLOS
Egypt	EEZ with Cyprus and Greece; rejects the Türkiye–Libya memorandum	2003 Cyprus and 2020 Greece agreements
Libya	Zones facing Türkiye under the 2019 memorandum, signed by the Tripoli-based government of the time	2019 MoU; domestic approval disputed
Israel and Lebanon	Zones in the southeastern basin, between themselves and with Cyprus	2010 Cyprus–Israel agreement; 2022 Israel–Lebanon arrangement
TRNC (Turkish Cypriots)	Equal and inherent rights over the island's offshore resources	1960 constitutional order; 2011 agreement with Türkiye; 2011, 2012 and 2019 cooperation proposals

Greece

According to the Greek Ministry of Foreign Affairs, Greece's position is that its islands generate continental shelf and EEZ under UNCLOS Article 121 and customary law, and that the only dispute with Türkiye is the delimitation of these zones. Athens has repeatedly proposed taking that dispute to the International Court of Justice. Greece also regards the Türkiye–Libya memorandum as ignoring Crete and as legally void, and it points to its 2020 agreements with Italy and Egypt as examples of delimitation on the basis of UNCLOS.

The Republic of Cyprus

The Republic of Cyprus, which Ankara refers to as the Greek Cypriot Administration of Southern Cyprus (GCASC), states that it is an UNCLOS party with sovereign rights over its EEZ and has licensed blocks accordingly. It says the Turkish Cypriots' interests will be protected, and in 2019 it proposed placing hydrocarbon revenues into a fund for the Turkish Cypriot community until a settlement. The Turkish Cypriot side has regarded such formulas as an unequal substitute for joint decision-making.

Egypt, Libya, Israel and Lebanon

Egypt signed with Cyprus in 2003 and with Greece in 2020 and rejected the Türkiye–Libya memorandum. Libya's 2019 memorandum was signed by the then Tripoli-based government; institutions in eastern Libya have contested it, which leaves its domestic standing unsettled. Israel, which is not an UNCLOS party, concluded its 2010 agreement with Cyprus and has focused on developing its own gas fields. Lebanon never ratified its 2007 agreement with Cyprus, and its 2022 arrangement with Israel settled one line without addressing the Cyprus-facing boundaries.

The European Union

European Council conclusions have backed the Republic of Cyprus and Greece and criticized the Türkiye–Libya memorandum as infringing the sovereign rights of third states. Ankara's reply is that the EU is not a party to the delimitation disputes and has no competence to decide them. For deeper treatment, see The Worldlogue: Can the European Union Decide Eastern Mediterranean Maritime Boundaries?.

🇹🇷 Official Policy · Primary Sources

Türkiye's Position

Ankara's case rests on two stated pillars: delimitation based on equity, and protection of the equal and inherent rights of the Turkish Cypriots. The points below are Ankara's official arguments, attributed to primary sources.

• Equity and proportionality govern delimitation. According to the Turkish Foreign Ministry, a mainland with the longest coastline in the basin cannot have its maritime projection cut off by small islands lying close to it. Ankara cites the ICJ's North Sea judgments (1969) and its later treatment of islands as special circumstances, for instance the limited effect given to Serpent Island in the 2009 Black Sea judgment. Source: Turkish MFA statements on maritime jurisdiction.
• The 870 km coastline is the factual base. Ankara argues that a median line drawn from remote islands would assign a narrow strip to Türkiye in the Gulf of Antalya and would be disproportionate to coastal lengths. It rejects the so-called Seville Map, a maximalist depiction attributed to Greek and Greek Cypriot claims. See What Is the Seville Map and Why Does Türkiye Reject It? and the sister analysis at The Global Anatomy: The Seville Map Explained.
• Turkish Cypriots have equal rights over offshore resources. Ankara and the TRNC state that the Turkish Cypriots are co-founders and equal co-owners of the island, so the Greek Cypriot administration cannot license blocks or sign EEZ agreements on behalf of the whole island. Ankara cites the 1960 constitutional partnership order and the 21 September 2011 Türkiye–TRNC agreement, signed two days after unilateral Greek Cypriot drilling began. The TRNC's 2011, 2012 and 2019 proposals for a joint committee and revenue sharing remain on the table. See Cyprus Dispatch: Why Federation Talks Stalled and What the Sovereign Equality Case Argues.
• The paper trail is documented at the UN. Türkiye points to its continental shelf coordinates lodged from 2004, the Libya memorandum of 27 November 2019 (approved by the TBMM) and the registration of its outer limits with the UN on 18 March 2020. Ankara argues that 2003 and later agreements between third parties that overlap its shelf, notably the Cyprus–Egypt agreement, are not opposable to Türkiye.
• The 2025 Marine Spatial Planning is a transparent record, and dialogue remains open. Ankara says that publishing the plan on 16 April 2025, having it recorded with IOC-UNESCO on 12 June 2025 and creating the inter-agency coordination board by the Presidential Circular of 24 July 2025 places its position across the Black Sea, Aegean and Mediterranean on record with a UN body for the first time. The plan was accompanied by the Finike Marine Protected Area. Ankara also points to President Erdoğan's 2020 call for an Eastern Mediterranean conference including all coastal states and the Turkish Cypriots, and argues that no energy or security arrangement excluding Türkiye and the TRNC can last.

Legal and historical basis

The legal basis cited by Ankara has three layers. First, UNCLOS Articles 74 and 83 themselves call for an equitable solution, which Türkiye reads as support for its proportionality argument even though it is not a party. Second, Ankara's position is that it consistently objected to the island-based approach of the 1982 Convention, which it opposed at adoption. Third, the Turkish Cypriot rights argument draws on the 1960 partnership arrangements and the Zurich and London Agreements of 1959. Other states dispute parts of this reading, as the next sections show.

Source Comparison

The same events are framed differently depending on which sources a reader consults. The table contrasts typical framings, based on the parties' own published positions.

Issue	Common Western and EU framing	Greek and Greek Cypriot official framing	Turkish primary-source framing
Basis of claims	UNCLOS as the governing framework	UNCLOS and Article 121 give islands full zones	Equity and customary law; UNCLOS Articles 74 and 83 support an equitable outcome
Türkiye–Libya MoU	Infringes third-state rights	Void; ignores Crete	Lawful bilateral agreement between states with facing coasts, approved by the TBMM
Drilling off Cyprus	Unauthorized activity in Cypriot waters	Violation of Cypriot sovereign rights	Exercise of Türkiye's own shelf rights and protection of Turkish Cypriot rights
Turkish Cypriot rights	Subject to a future settlement	Protected through a revenue fund after a settlement	Equal and inherent now, requiring joint decision-making
2025 IOC-UNESCO record	Largely a technical filing, without effect on boundaries	Unilateral maps have no legal effect	First recording of Türkiye's position with a UN body
EU role	Solidarity with member states	Natural defender of a member state	EU has no competence over delimitation between third parties

How to read the 2025 registration

Independent analysts point out that IOC-UNESCO is an oceanographic and scientific body that hosts a record of national maritime spatial plans. It does not adjudicate or recognize boundaries, and such plans cannot override treaty or court outcomes. Ankara does not claim otherwise in formal terms. Its argument is about transparency and record: that for the first time its Blue Homeland (Mavi Vatan) position, understood as Türkiye's maritime jurisdiction areas in the Black Sea, Aegean and Mediterranean, sits in a UN body's records. Greek and Greek Cypriot officials have answered that unilateral maps cannot create legal effects. Both readings can be held at once: the registration is a documentary step, not a delimitation.

For additional analysis of the law, see Doctrine Review: Eastern Mediterranean Maritime Jurisdiction and The Political Anatomy: Blue Homeland and Eastern Mediterranean Maritime Jurisdiction.

What to watch

• Whether Greece and Türkiye resume structured talks on delimitation and whether they accept a shared procedure, bilateral negotiation or the ICJ.
• Any further bilateral agreements by Egypt, Libya, Lebanon, Israel or Cyprus that overlap Türkiye's declared shelf.
• Offshore licensing and drilling by the Republic of Cyprus, and Turkish Cypriot responses on joint decision-making.
• How Libya's divided institutions treat the 2019 memorandum.
• The work of the inter-agency coordination board established under the Foreign Ministry in July 2025 and the management of the Finike Marine Protected Area.
• The capacity underpinning enforcement and survey activity, discussed in About 80% Domestic: How Türkiye's Defense Industry Shapes Regional Deterrence.

Key Terms & Related Guides

• Continental shelf: the seabed and subsoil extending from a coast; under UNCLOS Article 76 it exists as of right and can overlap with the neighbour's shelf.
• EEZ (exclusive economic zone): a zone up to 200 nautical miles (about 370 km) in which a coastal state has sovereign rights over resources; it must be delimited where coasts are closer than 400 nautical miles.
• Equity and proportionality: the principles courts use to adjust a provisional line so that the result is fair relative to coastal lengths and special circumstances.
• Blue Homeland (Mavi Vatan): Türkiye's concept of its maritime jurisdiction areas in the Black Sea, Aegean and Eastern Mediterranean, now expressed in the 2025 spatial plan.
• Marine Spatial Planning: a public process of allocating sea space among uses such as energy, shipping, fisheries and conservation; IOC-UNESCO promotes it as a global practice.
• GCASC and TRNC: the Greek Cypriot Administration of Southern Cyprus, as Türkiye terms the Republic of Cyprus government, and the Turkish Republic of Northern Cyprus, proclaimed on 15 November 1983 and recognized by Türkiye.

Related guides on Regional Observer:

• What Is the Seville Map and Why Does Türkiye Reject It?
• Cyprus Dispatch: Why Federation Talks Stalled and What the Sovereign Equality Case Argues
• The Annan Plan Referendum of 24 April 2004: 64.91% Yes, 75.83% No, and What Followed
• Fact Check: Was the 1974 Cyprus Operation an 'Illegal Invasion'? What Article IV of the Treaty of Guarantee Says
• Editorial Principles: How Regional Observer Separates Fact, Analysis and Türkiye's Position

Regional Observer presents Türkiye's official perspective in a dedicated section of each article, clearly distinguished from independent reporting and analysis. Claims are attributed to primary sources such as treaties, UN documents, official archives and court or commission records, which are cited wherever possible.

Regional Observer Editorial Team