Comprehensive Dossier· Blue Homeland Mavi Vatan UNCLOS maps IOC-UNESCO registration

The Blue Homeland Dossier: UNCLOS Articles, Maps and the 2025 IOC-UNESCO Registration

A document inventory of Blue Homeland (Mavi Vatan): UNCLOS Articles 74, 83, 121, UN deposits, maps, the Libya MoU and the 2025 IOC-UNESCO registration.

By Diplomatic Dossier Editorial Team

Published: October 27, 2026

⏱ 13 min read (2,784 words)

Executive Summary & Key Facts

Türkiye is not a party to UNCLOS: it voted against the Convention's adoption in 1982 and has not acceded, so Ankara invokes equity and customary law rather than treaty text.
UNCLOS Articles 74 and 83 require delimitation by agreement to reach an 'equitable solution', while Article 121 sets the island regime that Greece cites for Kastellorizo (Meis).
Türkiye's documentary track runs from UN notifications in 2004 through the 2011 TRNC agreement, the 27 November 2019 Libya memorandum and the 18 March 2020 UN deposit.
Türkiye's Marine Spatial Planning was unveiled on 16 April 2025 and recorded with IOC-UNESCO on 12 June 2025, a planning record that does not itself delimit any boundary.
Greece, the Republic of Cyprus, Egypt and the EU contest the Libya memorandum and Ankara's lines, so the dispute turns on what each document legally establishes.

Why It Matters

The Blue Homeland (Mavi Vatan) dispute is a dispute about which documents create maritime rights and which only assert them. Türkiye, which is not a party to the 1982 UN Convention on the Law of the Sea (UNCLOS), argues that delimitation must follow equity and the geography of its 870 km (about 540 mi) Eastern Mediterranean coastline. Greece, the Republic of Cyprus, Egypt and the European Union argue that UNCLOS, including its island provisions, supports their lines. This file inventories the principal legal texts, maps, deposits and registrations, and states what each one does and does not establish.

Background

How to Read This Dossier

Every entry below is classified by issuer, date and legal nature. The distinctions matter: a notification informs, a deposit publicises, a registration records, and only an agreement between the states concerned (or a binding judgment) delimits. Positions of other states are paraphrased from their official documents rather than quoted, so that nothing is attributed to them in words they did not use. Treaty text is quoted directly. For the method behind this approach, see How to Verify a Claim About Türkiye's Foreign Policy and our Editorial Principles.

The Legal Texts: UNCLOS Articles 74, 83 and 121

UNCLOS was adopted on 30 April 1982, opened for signature on 10 December 1982 and entered into force on 16 November 1994. Greece, the Republic of Cyprus and Egypt are parties. Türkiye voted against adoption in 1982 and has not signed or ratified it. Israel is also outside the treaty.

Provision	What the text says	How Greece, Cyprus, Egypt and the EU invoke it	How Ankara reads it
Article 74 (EEZ)	Delimitation between states with opposite or adjacent coasts is “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.”	Treated as binding on parties, and as reflecting customary law. Athens and Nicosia read it together with the island regime in Article 121 and with median-line practice.	Ankara stresses the phrase “equitable solution” and the requirement of agreement. Unilateral lines cannot be opposed to a state that has not agreed.
Article 83 (continental shelf)	Uses the same formula as Article 74 for the continental shelf.	Cited for the Cyprus–Egypt (2003) and Greece–Egypt (2020) lines.	Ankara argues that the shelf of the longest mainland coast cannot be cut off by small islands far from their mother country.
Article 121 (islands)	Paragraph 1: an island is “a naturally formed area of land, surrounded by water, which is above water at high tide.” Paragraph 2: its maritime zones are determined like other land territory. Paragraph 3: “Rocks which cannot sustain human habitation or economic life of their own shall have no exclusive economic zone or continental shelf.”	Greece argues that inhabited islands such as Kastellorizo (Meis) generate full entitlements under paragraph 2.	Ankara treats entitlement and delimitation effect as separate questions. It cites international case law that gave islands reduced or no effect in a delimitation.

Two further points frame the texts. First, Article 309 forbids reservations, which is one reason Ankara says it could not accept the package. Second, UNCLOS does not define the delimitation method. It prescribes the goal (an equitable solution) and leaves the method to agreement or adjudication.

The Maps and Coordinates

Four families of maps recur in the dispute:

The Blue Homeland map. The concept emerged in Turkish naval strategic writing in the 2000s and entered official discourse around the large-scale “Blue Homeland” naval exercise of 2019. It depicts Türkiye's claimed maritime jurisdiction in the Black Sea, Aegean and Mediterranean.
The Greek and Greek Cypriot maps. These give full effect to islands, including Kastellorizo, and draw lines on the median-line principle. Cyprus also publishes a grid of thirteen numbered offshore licensing blocks.
The Seville Map. A map linked to a University of Seville study that circulated in EU debates. Athens and Nicosia cite it, and Ankara says it has no legal standing. See What Is the Seville Map, and Why Does Türkiye Say It Has No Legal Standing?.
Treaty and deposit coordinates. The only legally operative map-like data are the coordinate lists attached to agreements (2011, 2019, 2020 Greece–Egypt) and to UN deposits. Readers should consult the original lists rather than redrawn media graphics.

A map shows a claim. It becomes a legal instrument only when attached to an agreement, a judgment or an accepted deposit.

Document Inventory

Date	Document	Issuer	What it establishes	What it does not establish
1982-04-30 / 1982-12-10	UNCLOS adopted, opened for signature	UN conference	Treaty regime for parties; Türkiye voted against	No boundary anywhere by itself
2003	Cyprus–Egypt EEZ agreement	Republic of Cyprus, Egypt	A line between the two parties	Türkiye objects that it overlaps its continental shelf (Cypriot blocks 1, 4, 5, 6 and 7)
2004 onward	Turkish notifications to the UN	Türkiye	Ankara's coordinates and objections placed on the UN record	No binding effect on other states; not a delimitation
2007 / 2010	Cyprus–Lebanon and Cyprus–Israel agreements	Republic of Cyprus and counterparts	Bilateral lines, which Cyprus defends as lawful	Türkiye and the TRNC say they disregard Turkish Cypriot rights; Lebanon has not ratified the 2007 text
2011-09-21	Türkiye–TRNC Continental Shelf Delimitation Agreement	Türkiye, TRNC	A bilateral line, signed two days after the Republic of Cyprus began drilling on 19 September 2011	Not recognised by Cyprus, the EU or the UN; UNSC Resolutions 541 (1983) and 550 (1984) call the TRNC's declaration legally invalid, and only Türkiye recognises it
2019-11-27	Türkiye–Libya maritime jurisdiction MoU	Türkiye, Libya's then Government of National Accord	A line between Turkish and Libyan coasts, in Ankara's reading	Rejected by Greece, Cyprus, Egypt and the EU; contested by Libya's eastern-based House of Representatives
2020-03-18	Deposit of outer limits of continental shelf	Türkiye to the UN	Official publicity of Ankara's coordinates	Not a review by the UNCLOS Commission on the Limits of the Continental Shelf; not recognition by others
2020-08-06	Greece–Egypt partial EEZ agreement	Greece, Egypt	A partial line between those two states	Ankara rejects it; it leaves the Greece–Türkiye question open
2025-04-16	Marine Spatial Planning of the Republic of Türkiye unveiled	Türkiye	A national plan for the uses of Turkish seas	A planning document is not a boundary treaty
2025-06-12	Plan recorded with IOC-UNESCO	Türkiye, IOC-UNESCO	Ankara's position recorded with a UN body for the first time	IOC-UNESCO is not a delimitation forum and does not endorse limits
2025-07-24	Presidential Circular	Presidency	Inter-Agency Coordination Board under the Foreign Ministry	Domestic governance, not an external legal act

The 2011 agreement sits within a wider Cyprus framework. For that background, see The Cyprus Case File: Zurich–London Texts, the Treaty of Guarantee and Article IV and The Annan Plan Referendum, 24 April 2004.

The 2025 IOC-UNESCO Step

On 16 April 2025 Türkiye unveiled its national marine spatial plan, and on 12 June 2025 it was recorded with IOC-UNESCO, the UNESCO body that coordinates ocean science and, through its marine spatial planning programme, planning guidance. A Marine Protected Area off Finike accompanied the plan. Ankara presents the record as the first time its position across the Black Sea, Aegean and Mediterranean has been lodged with a UN body. For a sister-publication explainer, see Monitor of Nations on the Marine Spatial Planning and IOC-UNESCO registration. Greece is bound by the EU's Maritime Spatial Planning Directive (2014/89/EU) and has pursued its own planning and marine-park measures. Greek officials have argued publicly that a unilateral plan cannot affect third states.

Key Players & Positions

Greece

Greece is an UNCLOS party and relies on Articles 74, 83 and 121. Athens argues that islands, including Kastellorizo, which lies roughly 2 km from the Turkish coast, generate full continental shelf and EEZ entitlements, and that the Türkiye–Libya memorandum ignores islands such as Crete. Greece says the only dispute to be settled is the delimitation of the continental shelf and EEZ with Türkiye, and has repeatedly offered to refer it to the International Court of Justice. Greece also reserves the right to extend its territorial sea to 12 nautical miles under UNCLOS Article 3. The Grand National Assembly of Türkiye (TBMM) answered that prospect with its 8 June 1995 resolution authorising the government to act.

Republic of Cyprus (Greek Cypriot administration)

Nicosia, the internationally recognised government of Cyprus and an EU member since 1 May 2004, holds that it is entitled to declare an EEZ and license blocks, and points to its agreements with Egypt (2003), Lebanon (2007) and Israel (2010). It has stated that hydrocarbon proceeds will benefit all Cypriots, with Turkish Cypriots sharing in them in the context of a settlement. It regards the 2011 Türkiye–TRNC agreement as having no legal effect.

Egypt

Egypt is an UNCLOS party and has defended its 2003 agreement with Cyprus and its 2020 partial agreement with Greece as lawful. Cairo has also objected to the Türkiye–Libya memorandum. Egyptian–Turkish relations were normalised in 2023–2024, with high-level visits in both directions. The maritime files have remained matters for legal and diplomatic exchange.

European Union

The European Council's conclusions of 12 December 2019 stated, in substance, that the Türkiye–Libya memorandum infringes the sovereign rights of third states, does not comply with UNCLOS and cannot produce legal consequences for third states. EU institutions also treat Cyprus's sovereign rights as a matter of solidarity with a member state.

Libya and the TRNC

The 2019 memorandum was signed by the Government of National Accord in Tripoli. Libya's eastern-based House of Representatives has contested it, and the document remains entangled in Libya's internal politics. The TRNC, which the Turkish Cypriot people proclaimed on 15 November 1983, is a co-signatory of the 2011 agreement, but its status is not recognised by UN members other than Türkiye.

🇹🇷 Official Position · Primary Sources on File

Türkiye's Position

Equity, not equidistance. Ankara argues that delimitation must produce an equitable result in light of coastal geography and proportionality, and that small islands near a mainland coast cannot cut off the mainland's projection. The Foreign Ministry (MFA) cites international case law, including the 1969 North Sea Continental Shelf cases, the 1977 Anglo-French Channel arbitration (where the Scilly Isles received half effect) and the 2009 Black Sea judgment (where Serpents' Island was not used in constructing the provisional line). The 1978 Aegean Sea Continental Shelf case, in which the Court found it lacked jurisdiction, remains part of the record.
UNCLOS is not binding on Türkiye. According to the MFA, Türkiye voted against the Convention in 1982 because it did not accommodate its security and equity concerns, and it remains outside the treaty. Ankara therefore relies on customary international law and on agreement between the states concerned (Articles 74 and 83 themselves require agreement), and treats unilateral lines drawn by others as non-opposable to it.
Turkish Cypriots are equal co-owners. The Turkish side holds that Turkish Cypriots, as co-founders of the 1960 Republic under the Zurich–London agreements and the Treaty of Guarantee, hold equal and inherent rights over offshore resources. The 2011 delimitation agreement and the TRNC's 2011, 2012 and 2019 proposals for a joint committee and revenue sharing are offered as the legal and practical expression of that position. See The Cyprus Case File.
A documentary track, built stage by stage. Ankara cites its UN notifications from 2004, TPAO exploration licences granted in 2009 and 2012, the 2011 agreement, the 27 November 2019 Libya memorandum and the 18 March 2020 deposit of its continental shelf outer limits. It adds the 2025 Marine Spatial Planning record with IOC-UNESCO, the Finike Marine Protected Area and the Presidential Circular of 24 July 2025 creating an Inter-Agency Coordination Board under the MFA. Field practice is supported by the drilling ships Fatih, Yavuz, Kanuni and Abdülhamid Han and the survey vessels Oruç Reis and Barbaros Hayreddin Paşa, which completed eight wells (Alanya-1, Finike-1, Karpaz-1, Güzelyurt-1, Mağusa-1, Narlıkuyu-1, Lefkoşa-1 and Selçuklu-1).
Dialogue is on the table, but the EU is not a delimitation authority. President Erdoğan proposed an Eastern Mediterranean Conference in 2020 that would include all coastal states and the Turkish Cypriots. Ankara rejects the Seville Map and maintains that the EU has no competence to adjudicate maritime delimitation on grounds of Union solidarity. Ankara argues that no energy or security arrangement that excludes Türkiye and the TRNC can last.

For sister-publication treatments of the doctrine, see Doctrine Review on continental shelf, EEZ and the Blue Homeland and The Nations Compass fact check on whether Türkiye violates UNCLOS.

Source Comparison

The same documents are described in different ways depending on the source. The table separates framing from what the text itself supports.

Issue	Common international / EU / Greek–Cypriot framing	Turkish primary-source framing	What the document itself shows
UNCLOS status	UNCLOS is the governing framework, and Türkiye is said to be acting outside it	Türkiye is a non-party that voted against; equity and custom govern	UNCLOS binds only parties by treaty. Arguments about custom must be tested against practice and case law
Islands	Article 121(2) gives islands full zones	Entitlement is not the same as delimitation effect; case law reduces or removes island effect	Article 121 sets entitlements. Articles 74 and 83 govern delimitation
Libya memorandum	Ignores islands and infringes third-state rights	A lawful agreement between two states with opposite coasts	A bilateral text. Whether third states' rights are affected is the core contest
2020 UN deposit	Unilateral and without legal weight	Official record of Türkiye's outer limits	A deposit publicises a claim. It is not an approval or a boundary
2025 IOC-UNESCO record	Unilateral, a mere planning exercise	First recording of Türkiye's position with a UN body	IOC-UNESCO records planning data and does not delimit
Cyprus resources	The Republic of Cyprus alone has jurisdiction, with benefit for all Cypriots	Turkish Cypriots are co-owners with equal rights	UNSC 541 and 550 and the 1960 treaties are both cited. Their reading is the contested point

The fairest conclusion from the paper record is limited. No document in this inventory creates a maritime boundary between Türkiye and Greece, or between Türkiye and the Republic of Cyprus, that both sides accept. Each side has created lines by agreement with partners and contested the others'. For another sister-publication view, see The Global Anatomy on the Seville Map.

Continental shelf: the seabed and subsoil extending from a coast, defined in UNCLOS Article 76. Under UNCLOS, it belongs to the coastal state without a need to proclaim it.
Exclusive economic zone (EEZ): a zone of up to 200 nautical miles (about 370 km) where the coastal state has sovereign rights over resources.
Equidistance / median line: a line every point of which is equally distant from the nearest points on each coast. Courts use it as a provisional step and adjust for relevant circumstances.
Equity (hakkaniyet): Ankara's central principle, referring to an equitable result in light of geography and proportionality.
Marine Spatial Planning (MSP): a process for organising the uses of sea areas. IOC-UNESCO promotes it as a governance tool.
TRNC: the Turkish Republic of Northern Cyprus, recognised only by Türkiye.
Blue Homeland (Mavi Vatan): the Turkish doctrine of maritime jurisdiction across the Black Sea, Aegean and Eastern Mediterranean.

Perspective Note

Diplomatic Dossier Editorial Team. Diplomatic Dossier presents Türkiye's official perspective and legal positions alongside the documentary record, and makes this editorial stance transparent to readers. Claims are attributed to primary sources such as treaties, UN documents, archival records, and official statements, so that readers can verify them independently. Sections marked 'Türkiye's Position' reflect official Turkish policy as stated by Turkish government sources.

Frequently asked questions

Is Türkiye a party to UNCLOS?

No. Türkiye voted against the adoption of the 1982 Convention and has neither signed nor ratified it. According to the Turkish Foreign Ministry, it relies on customary international law, the principle of equity and agreement between the states concerned. Greece, the Republic of Cyprus and Egypt are parties, and they argue that key UNCLOS rules reflect customary law that also binds Türkiye.

What do UNCLOS Articles 74, 83 and 121 actually say?

Articles 74 (EEZ) and 83 (continental shelf) require delimitation between states with opposite or adjacent coasts by agreement, to achieve an equitable solution. Article 121 says an island generates the same zones as other land territory, except that rocks that cannot sustain human habitation or economic life have no EEZ or continental shelf. Greece stresses the entitlement in Article 121(2), while Ankara stresses the equitable-solution test in Articles 74 and 83.

What did the 12 June 2025 IOC-UNESCO registration do?

It recorded Türkiye's Marine Spatial Planning, unveiled on 16 April 2025, with a UN body, which Ankara presents as the first time its maritime position across three seas has been lodged there. It does not delimit any boundary, and IOC-UNESCO does not endorse or reject limits. Greece and others argue that it has no legal effect on third states.

Did the 18 March 2020 UN deposit mean the UN approved Türkiye's continental shelf limits?

No. Türkiye deposited the coordinates of its outer limits with the UN, which makes them publicly available. It was not a submission to the UNCLOS Commission on the Limits of the Continental Shelf, which serves parties, and no review or endorsement followed. Ankara regards the deposit as formal notice of its position.

Why do Greece, Cyprus, Egypt and the EU reject the 2019 Türkiye–Libya memorandum?

They argue that it ignores islands such as Crete and infringes the sovereign rights of third states. The European Council said in December 2019 that it cannot produce legal consequences for third states. Türkiye replies that it is a lawful bilateral agreement between two states with opposite coasts and that an equitable solution requires reduced effect for distant islands.

Where can I read the original documents?

UNCLOS and the UN's maritime notifications are available through the UN Division for Ocean Affairs and the Law of the Sea. The Turkish Foreign Ministry publishes its maritime-jurisdiction statements, and the Presidency and Directorate of Communications publish speeches and circulars. Our guide on verifying claims about Türkiye's foreign policy lists where to find each type of text.

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