What Is a NAVTEX, and What Can It Legally Do? Reading Antalya NAVTEX 1127/26 and the Great Sea Interconnector Survey Dispute

Why It Matters

A NAVTEX is a maritime safety broadcast that warns mariners; it does not create, transfer or extinguish sovereign rights. Yet in the Eastern Mediterranean, where Greece, Cyprus, Türkiye and the EU disagree over cable surveys for the Great Sea Interconnector, rival NAVTEX notices such as Antalya 1127/26 have become a public record of each side's legal position.

The notice is the third paper-trail instrument in the cable dispute, after diplomatic notifications and public statements. Reading it correctly means separating what a navigational warning can do (inform and signal) from what only treaties, delimitation agreements or adjudication can do (allocate maritime rights). This guide does not predict escalation; the question of consent remains legally contested.

Background

NAVTEX is an automated maritime safety information broadcast used within the Global Maritime Distress and Safety System and the IMO/IHO World-Wide Navigational Warning Service, under the SOLAS framework. The Great Sea Interconnector survey dispute reported on 10 November 2026 is the latest episode in a longer paper trail of notices, notes and objections.

What is a NAVTEX, and is it a legal instrument?

NAVTEX (short for Navigational Telex) delivers maritime safety information such as navigational and meteorological warnings to ships by automated narrow-band direct printing, with 518 kHz used internationally for English-language messages. Under the IMO/IHO World-Wide Navigational Warning Service, the oceans are divided into numbered NAVAREAs (with METAREAs for meteorological information), each with a coordinator. The Mediterranean falls in NAVAREA III, coordinated by Spain. Coastal states broadcast local warnings through their own NAVTEX stations, and SOLAS Chapter V (Regulation 4) obliges contracting governments to arrange for navigational warnings to be issued. Typical subjects include survey work, cable-laying, drilling, exercises and hazards to navigation.

The plain answer is that a NAVTEX is not a legal instrument in the sense of a treaty, a delimitation agreement or a court order. It warns mariners. It does not create, transfer or extinguish sovereign rights, and no state can acquire a maritime zone by broadcasting a notice.

States nonetheless use NAVTEX as a signalling and record-keeping tool in disputed waters for three reasons:

• It is public, dated and numbered, so it leaves a verifiable trace.
• It reaches the vessels that are physically present in the area.
• In the law of state responsibility and territorial and maritime disputes, tribunals weigh the whole pattern of conduct. A notice can be evidence of a state's claimed position, of a protest, or, if no objection follows, of acquiescence. Its weight depends on consistency and context, not on the notice alone.

How does a NAVTEX differ from a note verbale or a démarche?

A NAVTEX speaks to mariners and to anyone who monitors the broadcast; a note verbale or démarche speaks state to state. For the diplomatic instruments, see our guides on what is a note verbale in diplomacy and how it differs from a démarche and on what is a note verbale, and our analysis of the French notification of Great Sea Interconnector works.

Instrument	Audience	Public or private	Legal character	Function
NAVTEX	Mariners and any monitoring party	Public broadcast	Operational safety notice; creates no rights	Warns of activity; signals and records a position
Note verbale	Another state or an international organisation	Usually private, public if circulated (e.g. at the UN)	Formal diplomatic communication; can carry protest or reservation	Registers legal positions on the record
Démarche	A foreign government, via its diplomats	Usually private	Political-diplomatic; not a formal legal act	Requests, warns or explains
Public statement	General public and other governments	Public	Political; legal weight varies with content	Signals policy and frames the narrative

What does the law of the sea say about cables on the continental shelf?

Article 79 of the 1982 UN Convention on the Law of the Sea (UNCLOS) is the key text. Its paragraphs say, in substance:

• Paragraph 1: all states are entitled to lay submarine cables and pipelines on the continental shelf.
• Paragraph 2: subject to its right to take reasonable measures for the exploration of the continental shelf, the exploitation of its natural resources and the control of pollution from pipelines, the coastal state may not impede the laying or maintenance of such cables or pipelines.
• Paragraph 3: the delineation of the course for the laying of such pipelines on the continental shelf is subject to the consent of the coastal state.

The interpretive disagreement is real. Greece, Cyprus and the EU, all UNCLOS parties, rely on paragraph 1 and the freedom to lay cables. They read paragraph 3 as applying to pipelines only. Others observe that paragraph 2 preserves coastal-state measures and that cable-route surveys may touch on marine scientific research, which Part XIII (Article 246) subjects to coastal-state consent on the shelf; whether a cable-route survey falls under that regime is itself debated.

Türkiye is not a party to UNCLOS. It relies on customary international law and on the principle of equity in delimitation. A further point is easily missed: Article 79 presupposes that one knows whose continental shelf is concerned. Here the underlying disagreement is precisely about delimitation, which is why the Seville Map and EU competence question matters. For a parallel reading of the rival notices, see Politics Meridian's fact check on the seabed cable survey southeast of Crete and the rival NAVTEX warnings.

Why does the survey stage matter?

The survey is the first physical step, and each stage of a cable project carries different diplomatic weight. Consent to, or silence about, an early step can be argued later as acceptance of the premise that the coastal state has a say, or of its absence.

Stage	What happens	Diplomatic significance
Seabed survey	Vessel maps and samples the route	First physical presence; objection or consent is recorded; may engage marine scientific research rules
Installation	Cable is laid along the chosen course	Article 79(3) arguments about the 'course' and coastal-state measures become sharper
Operation and maintenance	Cable is in service; repair vessels return	Permanent presence; Article 79(5) 'due regard' to cables already in position

Tribunals generally look at cumulative conduct, and consent must normally be clear and attributable to an authorised state organ. A claim of consent in a NAVTEX therefore does two things: it frames the survey as coordinated, and it creates a record that the other side must either accept or contest.

Key Players & Positions

According to Greek City Times on 10 November 2026, the French research vessel Abeille Marengo left Heraklion to resume Great Sea Interconnector seabed surveys, and Antalya NAVTEX 1127/26 claimed coordination with and consent from Turkish authorities. Athens rejected that claim, saying work proceeds under Greek and Cypriot permits; French naval vessels were reportedly deployed in support.

What NAVTEX 1127/26 claims

Per Greek City Times, the Antalya NAVTEX station issued notice 1127/26 stating that the planned research activities had been coordinated with Turkish authorities and had received their consent. Diplomat Note has not independently verified the full text of the notice, and we have not seen Turkish official confirmation of its wording in the reporting available to us. Readers should consult the broadcast text and official releases directly.

Greece and Cyprus

Greek City Times reports that Athens rejected Ankara's assertion and reaffirmed that the project proceeds under permits issued by Greek and Cypriot authorities. Greece and Cyprus present the cable as a lawful exercise of the freedom to lay cables under UNCLOS. Official statements of the Greek Foreign Ministry and the Hellenic Navy are the primary sources for this position; we have not reviewed their full texts here.

France

France is the flag state of the survey vessel, as reported. Greek City Times, in a separate report, said French naval vessels reportedly sailed for the wider research area to provide an escort and protective presence. It also reported that France notified Türkiye of the works, a step we analyse in our guide to the French notification. We found no French official statement in the reporting available, so deployment details remain reported rather than confirmed.

The EU

EU institutions treat the Great Sea Interconnector as an energy-infrastructure project of European interest. The Commission's 4 November enlargement findings addressed, among other things, the Cyprus cable; for what such a report can and cannot settle, see our guide to the legal weight of the EU Enlargement Report. Lines of Power examines the corridor argument in When a Cable Becomes a Corridor.

🇹🇷 Official Policy · Primary Sources

Türkiye's Position

Ankara holds that Great Sea Interconnector activity on continental shelf Türkiye registered with the United Nations on 18 March 2020 requires coordination with Türkiye, and that the rights of Turkish Cypriots and the TRNC must be respected. It argues that delimitation must be agreed on the basis of equity rather than settled by unilateral activity.

• Registered shelf and coordination. According to the Turkish Ministry of Foreign Affairs (MFA), Türkiye deposited the outer limits of its continental shelf with the UN on 18 March 2020. Ankara holds that the GSI route crosses areas covered by that registration and that activity there needs coordination with Türkiye. This is the logic Ankara attaches to a NAVTEX such as 1127/26.
• Turkish Cypriot rights. Ankara argues that the Turkish Cypriots, as co-founders of the 1960 Republic, have equal rights over the island's offshore areas and must take part in decisions on them. The Türkiye–TRNC Continental Shelf Delimitation Agreement of 21 September 2011 is the treaty reference point in MFA statements.
• Equity and the 870 km coastline. Türkiye has the longest mainland coastline in the Eastern Mediterranean (870 km). The MFA maintains that islands cannot cut off a mainland's maritime projection and that maritime areas must be delimited by agreement on the basis of equity. Ankara points to the Türkiye–Libya Memorandum of Understanding of 27 November 2019 as an application of that approach.
• Marine Spatial Planning record. The Marine Spatial Planning of the Republic of Türkiye, announced on 16 April 2025 and registered with IOC-UNESCO on 12 June 2025, records Türkiye's maritime jurisdiction position across the Black Sea, the Aegean and the Mediterranean. The Presidential Circular of 24 July 2025 set up an inter-agency coordination board under the MFA.
• Dialogue offer. Ankara points to President Erdoğan's 2020 proposal for an Eastern Mediterranean Conference including all coastal states and the Turkish Cypriots, and argues that a project excluding Türkiye and the Turkish Cypriots cannot be sustainable. On 10 November 2026, TRT World reported that MFA spokesperson Öncü Keçeli welcomed progress at the 9 November trilateral meeting on the island between TRNC President Tufan Erhürman, the Greek Cypriot leader and the UN Secretary-General's personal envoy, and urged the Greek Cypriot Administration to change its stance. Ankara links confidence-building on the island to a cooperative regional approach.

These positions are set out in statements from the MFA, the Ministry of National Defence, the Presidency and the Directorate of Communications. The legal basis Ankara invokes is customary law, the equity principle and the 1960 partnership structure, not UNCLOS, to which it is not a party. For the wider record, see The Paper Trail of the Blue Homeland.

Source Comparison

Greek and Cypriot outlets such as Greek City Times present the survey as a project proceeding under Greek and Cypriot permits and the NAVTEX as an Ankara claim, while Turkish official sources ground Türkiye's position in its registered continental shelf and the principle of equity. The table separates what each source states as fact from what it asserts as a legal conclusion.

Source	Stated as fact	Asserted as legal conclusion
Greek and Cypriot outlets (e.g. Greek City Times)	Abeille Marengo left Heraklion on 10 November 2026; Antalya issued NAVTEX 1127/26; French naval vessels reportedly deployed	The project proceeds lawfully under Greek and Cypriot permits; the claim of Turkish consent is rejected
EU institutions	The GSI is an EU-backed energy-interconnection project; the Commission's 4 November report addresses the cable	Broadly, the freedom to lay cables under UNCLOS applies
Turkish official sources (MFA and others)	Türkiye registered its shelf limits with the UN on 18 March 2020; the 2011 TRNC and 2019 Libya instruments exist	Activity on the registered shelf needs coordination; Turkish Cypriots must participate; delimitation must rest on equity

Two cautions follow. First, no NAVTEX, report or note settles ownership of the seabed. Second, the Commission's findings cannot delimit a boundary, a point tested in Mirror of States' mirror test of the 4 November report. Our editorial principles explain how we attribute contested claims.

Key Terms & Related Guides

Key terms such as NAVTEX, NAVAREA/METAREA, continental shelf, EEZ, consent, acquiescence and protest explain how a navigational warning becomes legal evidence. The glossary below defines each and links to related Diplomat Note guides on notes verbales, the Seville Map and the Blue Homeland paper trail.

• NAVTEX: automated broadcast of maritime safety information to ships.
• NAVAREA/METAREA: the 21 areas of the IMO/IHO World-Wide Navigational Warning Service, each with a coordinator; the Mediterranean is NAVAREA III.
• Continental shelf: the seabed and subsoil over which a coastal state exercises sovereign rights for exploring and exploiting resources (UNCLOS Article 77).
• EEZ: the exclusive economic zone, up to 200 nautical miles, where the coastal state has sovereign rights over resources.
• Consent: a state's clear, attributable agreement to an activity; it does not automatically extend to later activities.
• Acquiescence and protest: silence in the face of a claim can be read as acceptance, while timely protest preserves a position.

Related guides:

• What is a note verbale in diplomacy: difference from démarche
• What is a note verbale
• France notifies Türkiye of Great Sea Interconnector works
• The Blue Homeland paper trail
• The Seville Map explained

Diplomat Note presents analysis from a Türkiye-informed perspective, grounded in Türkiye's official legal and strategic positions. Claims are attributed to primary sources such as treaty texts, UN and IOC-UNESCO documents, official archives and public statements, so that readers can verify them independently. This article is published by the Diplomat Note Editorial Team; see About Diplomat Note.