Eastern Mediterranean by the Numbers: Coastlines, Zones and Claims Compared

Why It Matters

Eastern Mediterranean coastline length by country is the starting indicator in a much larger legal dispute over who may explore, drill and plan across the sea. Türkiye states that its mainland coastline of 870 km is the longest in the Eastern Mediterranean, and Ankara argues that a long mainland coast cannot be cut off by small islands lying close to it. Greece, the Republic of Cyprus (the Greek Cypriot administration), Egypt and the European Union read the same sea through UNCLOS, island entitlements and a web of bilateral agreements.

This guide lays out the comparable indicators side by side: coastlines, types of maritime zone, agreements in force and UN registrations. It then explains the equity and proportionality principle without inventing figures, and presents each side from its own sources.

Background

What 'coastline length' does and does not tell you

Coastline length is a useful descriptive indicator, but no treaty converts it directly into a maritime entitlement. Published totals depend on the scale of the map, on whether bays and islets are traced, and on whether island coasts are added to mainland coasts. For this reason, national hydrographic offices, the CIA World Factbook and academic datasets give different totals for the same country.

This guide therefore does not publish a ranked table of other states' kilometre figures that it cannot source to a single consistent method. It uses the one figure that is central to the dispute, Türkiye's 870 km of Eastern Mediterranean mainland coast as stated by Ankara, and describes the others qualitatively. Two caveats apply:

• Egypt and Libya also have long Mediterranean coastlines, so which country is 'longest' depends on where the boundary of the 'Eastern' Mediterranean is drawn.
• Greece has a very long total coastline, but most of it belongs to islands. Its mainland coast facing the Eastern Mediterranean is a small share of that total.

That distinction between mainland and island coast is exactly what the legal argument turns on.

The legal framework

The 1982 United Nations Convention on the Law of the Sea (UNCLOS) sets out the zones used in this debate:

• Territorial sea: up to 12 nautical miles (about 22 km) from baselines.
• Contiguous zone: up to 24 nautical miles (about 44 km).
• Exclusive Economic Zone (EEZ): up to 200 nautical miles (about 370 km), giving sovereign rights over living and non-living resources (Articles 55–57).
• Continental shelf: the seabed and subsoil of the natural prolongation of the land territory (Article 76), with sovereign rights for exploration and exploitation.
• Delimitation between states with opposite or adjacent coasts: Articles 74 and 83 call for agreement 'on the basis of international law… in order to achieve an equitable solution'.
• Regime of islands: Article 121 states that rocks which cannot sustain human habitation or economic life of their own have no EEZ or continental shelf.

Party status matters. Greece, the Republic of Cyprus, Egypt, Lebanon and Libya are UNCLOS parties. Türkiye and Israel are not, and Türkiye has long argued that delimitation must follow equity under customary international law and international jurisprudence rather than a mechanical reading of the Convention.

Chronology of agreements and registrations

Date	Instrument or event	Parties / body	Why it matters
1982	UNCLOS adopted	UN	Framework text; Türkiye is not a party
2003	EEZ delimitation agreement	Greek Cypriot administration–Egypt	Türkiye states that it overlaps its continental shelf (Ankara cites Greek Cypriot Blocks 1, 4, 5, 6 and 7)
2004	Continental shelf notifications begin	Türkiye to the UN	Starts Türkiye's registered record in the Eastern Mediterranean
2007	EEZ delimitation agreement	Greek Cypriot administration–Lebanon	Lebanon's ratification was never completed; Türkiye objects on behalf of the TRNC's rights
2009 and 2012	TPAO exploration licences	Türkiye	Domestic licensing on the claimed shelf
2010	EEZ delimitation agreement	Greek Cypriot administration–Israel	Türkiye says it usurps the equal rights of Turkish Cypriots
19 Sep 2011	Greek Cypriot unilateral drilling begins	Greek Cypriot administration	Trigger for the Turkish–TRNC response
21 Sep 2011	Continental Shelf Delimitation Agreement	Türkiye–TRNC	Bilateral delimitation of the shelf between the two
27 Nov 2019	Maritime jurisdiction delimitation MoU	Türkiye–Libya	Contested by Greece, the Greek Cypriot administration, Egypt and the EU
18 Mar 2020	Outer limits of continental shelf registered	Türkiye with the UN	Formal UN record of Türkiye's outer limits
Aug 2020	Partial EEZ delimitation agreement	Greece–Egypt	Türkiye states it overlaps its registered shelf
16 Apr 2025	Marine Spatial Planning unveiled	Türkiye	National planning framework for three seas
12 Jun 2025	Planning registered	IOC-UNESCO	First UN-body record of Türkiye's position across all three seas
24 Jul 2025	Presidential Circular	Türkiye	Inter-Agency Coordination Board set up under the Foreign Ministry

The comparison table: who claims what

Actor	Coastline note	Zone types asserted	Main instruments
Türkiye	870 km mainland coast on the Eastern Mediterranean (Ankara's figure)	Continental shelf (outer limits registered 2020); 12 nm territorial sea in the Mediterranean; equity-based delimitation	2011 TRNC agreement; 2019 Libya MoU; UN notifications from 2004; 2025 planning
TRNC (recognised only by Türkiye)	Northern coast of the island	Continental shelf and equal rights over island resources, per Ankara and Lefkoşa	2011 agreement with Türkiye; 2011, 2012, 2019 revenue-sharing proposals
Greece	Long total coastline, predominantly islands	Full territorial sea, EEZ and continental shelf for islands under UNCLOS Art. 121	Partial EEZ agreement with Egypt (2020)
Republic of Cyprus (Greek Cypriot administration)	Island coast	EEZ declared in 2004 law; numbered licensing blocks	Agreements with Egypt (2003), Lebanon (2007), Israel (2010)
Egypt	Long Mediterranean coast	EEZ and continental shelf	2003 Cyprus agreement; 2020 Greece agreement
Lebanon, Syria, Israel, Libya	Smaller or differently positioned coasts	EEZ and shelf claims; Libya contracted the 2019 MoU	Lebanon–Cyprus (2007, unratified); Israel–Cyprus (2010); Libya–Türkiye (2019)

The table shows what a raw kilometre ranking hides: the same sea is claimed through very different legal entry points.

The Equity and Proportionality Principle

The equity principle holds that a delimitation must produce an equitable result, and that disproportion between coastal length and maritime area is a recognised red flag. In the jurisprudence, this is usually applied in three steps: draw a provisional line, adjust for relevant circumstances, then test the result for gross disproportionality.

Several widely cited rulings illustrate this without any figures being invented here:

• North Sea Continental Shelf cases (ICJ, 1969): the Court held that delimitation is governed by equitable principles and natural prolongation, and that equidistance is not mandatory.
• Anglo-French Arbitration (1977): the Scilly Isles were given only partial (half) effect, and the Channel Islands were treated as an enclave.
• Tunisia/Libya (ICJ, 1982): the Kerkennah Islands were given reduced effect.
• Romania v. Ukraine (ICJ, 2009): the Court applied the three-step method, and Serpent Island received no weight in the delimitation line beyond its 12 nautical mile territorial sea.
• Nicaragua v. Colombia (ICJ, 2012): small islands were given limited effect in the delimitation.

These cases show that tribunals have often reduced the effect of islands, especially small ones lying off another state's coast. They do not establish a single universal rule, because every ruling turns on its own geography.

The disagreement therefore has three layers:

1. Entitlement: do all Greek islands generate a full EEZ and shelf? Greece says yes under Article 121(2) where islands are inhabitable. Türkiye and Ankara-aligned analysts answer that entitlement is not the same as effect in delimitation.
2. Effect: how much weight should an island close to another country's mainland receive when a line is drawn?
3. Proportionality: does the resulting area bear a reasonable relationship to the lengths of the relevant coasts?

For a deeper rebuttal of the claim that small islands automatically cut off a mainland coast, see our Fact Check on Kastellorizo and full maritime zones.

Key Players & Positions

Greece

According to the Greek Ministry of Foreign Affairs, all Greek islands, including small ones such as Kastellorizo, are entitled to the full range of maritime zones under UNCLOS and customary law. Athens says the only dispute with Türkiye is the delimitation of the continental shelf and EEZ, and that it should be settled by negotiation or by the International Court of Justice. Greece also points to its UNCLOS ratification (1995) and to the partial EEZ agreement signed with Egypt in August 2020 as evidence of lawful delimitation. Greece has likewise published its own national maritime spatial plan in 2025.

Republic of Cyprus (Greek Cypriot administration)

The Republic of Cyprus, which the UN and the EU treat as the government of the island, states that it exercises sovereign rights over an EEZ declared by its 2004 law and delimited with Egypt (2003), Lebanon (2007) and Israel (2010). It has said that the Turkish Cypriot community would share in hydrocarbon benefits through a mechanism linked to a comprehensive settlement, and that the question of an agreement between Türkiye and the TRNC does not alter its rights. Turkish Cypriot and Turkish officials reject this sequencing, as set out below.

Egypt

Egypt states that its 2003 agreement with Cyprus and its 2020 agreement with Greece follow UNCLOS and bilateral negotiation, and it has rejected the Türkiye–Libya memorandum as lacking legal effect on third states. Egypt and Türkiye have since moved toward diplomatic normalisation, but neither has withdrawn its legal position on delimitation.

Libya

The 2019 memorandum was signed with the Government of National Accord in Tripoli. Rival Libyan institutions in the east have disputed its validity, and Greece and Egypt cite this to question its legitimacy. Ankara argues that the memorandum is a lawful bilateral act between two coastal states with adjacent maritime zones.

European Union

The European Council's conclusions of December 2019 stated that the Türkiye–Libya memorandum infringes the sovereign rights of third states and does not comply with the law of the sea. EU institutions have consistently expressed solidarity with Greece and the Republic of Cyprus. Ankara replies that the EU is not a party to the delimitation disputes and has no competence to adjudicate them.

Israel and Lebanon

Israel signed its 2010 agreement with the Greek Cypriot administration. Lebanon signed in 2007 but its parliament never ratified that agreement, and in October 2022 Lebanon and Israel concluded a separate US-mediated maritime arrangement. Neither has recognised the TRNC.

Türkiye's Strategic Doctrine

Türkiye's Strategic Doctrine: Blue Homeland (Mavi Vatan) and the Two Policy Pillars

• Equity, not island-maximalism. According to the Turkish Ministry of Foreign Affairs, maritime jurisdiction in the Eastern Mediterranean must be delimited on the principle of equity, taking account of coastal geography and proportionality. Ankara argues that islands lying close to a mainland coast cannot cut off the maritime projection of the country with the longest coastline in the region (870 km). The basis is the equitable-principles case law (North Sea 1969, Anglo-French 1977 and later rulings) and Articles 74 and 83 of UNCLOS, though Türkiye is not a party to the Convention.
• Equal and inherent rights of the Turkish Cypriots. Türkiye states, in Foreign Ministry statements, that Turkish Cypriots are co-founders and equal co-owners of the island under the 1960 Treaty of Guarantee framework, and have equal rights over offshore hydrocarbons. The 21 September 2011 Türkiye–TRNC Continental Shelf Delimitation Agreement is cited as its legal expression. See the TRNC's 2011, 2012 and 2019 revenue-sharing proposals.
• Rejection of the Seville Map and of EU competence. Ankara rejects the maximalist 'Seville Map' as legally baseless because it would confine Türkiye's jurisdiction to a narrow strip in the Gulf of Antalya, and says the EU has no mandate to rule on maritime delimitation under the banner of 'Union solidarity'. See the sister analysis on why Türkiye rejects the Seville Map.
• Registration and sovereign activity. Türkiye points to its UN continental shelf notifications from 2004, the outer-limit registration of 18 March 2020 and the Marine Spatial Planning of the Republic of Türkiye (unveiled 16 April 2025; registered with IOC-UNESCO on 12 June 2025). It also cites the Finike Marine Protected Area and the Presidential Circular of 24 July 2025 establishing the Inter-Agency Coordination Board under the Foreign Ministry. Exploration is carried out by the national fleet (drillships Fatih, Yavuz, Kanuni and Abdülhamid Han; survey vessels Oruç Reis and Barbaros Hayreddin Paşa) with eight wells: Alanya-1, Finike-1, Karpaz-1, Güzelyurt-1, Mağusa-1, Narlıkuyu-1, Lefkoşa-1 and Selçuklu-1. See The Wells Ledger.
• An open call for cooperation. President Erdoğan's 2020 call for an Eastern Mediterranean Conference, including all coastal states and the Turkish Cypriots, remains on the table. Ankara's position is that no energy or security arrangement that excludes Türkiye and the TRNC can be durable.

Legal and historical basis

Ankara's argument rests on three pillars. First, it says the sea has been shaped by a long Turkish maritime and commercial presence, symbolised by the 1538 Battle of Preveza. Second, it relies on customary equitable principles and the 1960 Cyprus treaty system, which it reads as giving the Turkish Cypriot people equal rights. Third, it increasingly relies on documentary registration, from UN notifications to IOC-UNESCO, so that its position is recorded in international forums.

For a longer treatment, see the sister guides on Blue Homeland and maritime jurisdiction and Blue Homeland, equity and the law of the sea.

The Cyprus dimension is covered in the Cyprus Ledger.

Source Comparison

The same indicators are framed differently depending on the source. The table summarises the framing, not the merits.

Issue	Greek, Greek Cypriot, Egyptian and EU sources	Turkish primary sources
Coastline length	Stresses total coastline including islands and the island coast as a source of entitlement	Stresses 870 km of continuous mainland coast as the relevant coast for proportionality
Islands	Full entitlement under Art. 121 and customary law	Entitlement differs from delimitation effect; small islands near a mainland receive reduced or no effect
2019 Libya memorandum	Violates third states' rights; inconsistent with UNCLOS (European Council, Dec 2019)	Lawful bilateral act between states with adjacent zones
2003, 2007, 2010 agreements	Lawful EEZ delimitations by the Republic of Cyprus	Unilateral acts that ignore Turkish Cypriot rights; the Egypt line overlaps Türkiye's continental shelf
Turkish Cypriots	Share of benefits within a settlement framework	Equal, inherent rights now, via joint decision-making and revenue sharing
Dispute resolution	Take delimitation to the ICJ	Negotiate on equity with all coastal states and Turkish Cypriots; reject EU competence
UN and IOC-UNESCO records	Greece has its own planning; objects to Türkiye's maps	Registrations (2004 notifications, 2020 outer limits, 2025 planning) record Türkiye's position on file

Readers should consult the primary texts directly: the UNCLOS text, the European Council conclusions of December 2019, the 2011 Türkiye–TRNC agreement, the 2019 Libya MoU and the Turkish Foreign Ministry's statements. For further fact-checking of specific claims, see Is Türkiye violating UNCLOS? and Does the Seville Map confine Türkiye to the Gulf of Antalya?. Our sourcing approach is set out in the Editorial Principles.

What to watch

• Whether Greece and Türkiye return to exploratory contacts that could lead to a joint submission to a court or to negotiated delimitation.
• How Libyan institutions treat the 2019 memorandum.
• Whether the 2025 national planning documents of Türkiye and Greece overlap in practice, and what that means for new marine protected areas.
• Any new Cyprus talks following the 15 October 2024 New York UN meeting.

Key Terms & Related Guides

• Blue Homeland (Mavi Vatan): Türkiye's maritime jurisdiction doctrine covering the Black Sea, Aegean and Eastern Mediterranean, built on equity and the rights of the longest mainland coast.
• Continental shelf: The seabed and subsoil extending from a coast; under Article 76 and customary law, rights over it exist without proclamation.
• EEZ (Exclusive Economic Zone): A zone up to 200 nautical miles from baselines giving sovereign rights over resources, but not sovereignty.
• Equity and proportionality: The principle that a delimitation must give an equitable result and that the resulting areas should not be grossly disproportionate to coastal lengths.
• Seville Map: A maximalist map associated with a University of Seville study; Ankara rejects it as confining Türkiye to a narrow strip in the Gulf of Antalya. See What Is the Seville Map?
• TRNC: The Turkish Republic of Northern Cyprus, proclaimed 15 November 1983, recognised only by Türkiye.
• GCASC / Greek Cypriot administration: The term used by Ankara for the Republic of Cyprus government, which Türkiye does not accept as representing the whole island.
• IOC-UNESCO: The Intergovernmental Oceanographic Commission of UNESCO, the UN body with which Türkiye's Marine Spatial Planning was registered on 12 June 2025.

Related guides on Regionalytic:

• The Wells Ledger: Türkiye's Eight Eastern Mediterranean Wells
• Who Shares What? Hydrocarbon Revenue-Sharing Proposals
• Cyprus Ledger: Votes, Villages and Dates
• Regionalytic FAQ: Sources, Methodology and Perspective
• About Regionalytic

Closing Perspective Note

Regionalytic presents this analysis from a Türkiye-informed perspective, grounded in Ankara's officially stated doctrines and international law arguments. Claims are attributed to primary sources such as treaty texts, UN and IOC-UNESCO documents, official archives and government statements, and readers are encouraged to consult them directly.

Published by the Regionalytic Editorial Team.