By Bosphorus News Geopolitics Desk
The seabed survey campaign that brought Greek and Turkish naval units into the same waters off Kasos in July 2024 is being prepared for a new phase, with a French vessel expected to carry out unfinished work on the Greece-Cyprus electricity interconnector.
Kathimerini reported on Sept. 14 that French President Emmanuel Macron had agreed that the vessel conducting seabed soundings for French cable manufacturer Nexans would sail under the French flag. France would also inform Türkiye and other nearby coastal states before the survey and cable-laying work begins.
Neither the Élysée nor Nexans has publicly confirmed those details.
Greek Prime Minister Kyriakos Mitsotakis and Macron discussed the next steps for the Great Sea Interconnector (GSI) at the Élysée Palace on Sept. 9. The Greek Prime Minister's Office linked the discussion to French infrastructure investor Meridiam becoming majority shareholder in GSI but made no reference to the vessel's flag or the notification arrangements later reported by Kathimerini.
Türkiye had already described what it expects if work resumes in maritime areas where it claims sovereign rights and jurisdiction. Turkish sources told Kathimerini on Aug. 26 that Ankara does not oppose submarine cables or international connectivity projects, but said vessels carrying out surveys or cable-laying in such areas should have their flag state contact Türkiye through diplomatic channels before work begins to coordinate the activity and avoid conflict.
A second Kathimerini report on Aug. 31 quoted officials in Ankara saying Türkiye had no intention of obstructing infrastructure projects but would act to protect its interests if a project were used to create what it regarded as faits accomplis in the Eastern Mediterranean.
The Turkish position calls for prior communication and coordination. Athens says notifying Ankara does not mean seeking Turkish permission.
If the French-flag arrangement reported on Sept. 14 goes ahead, France would become the state making the contact Ankara says it expects from the vessel's flag state.
France Moves Deeper Into GSI
Meridiam became GSI's majority shareholder in August, taking a 66% stake, while a separate agreement between Greece's Independent Power Transmission Operator (IPTO), GSI and Nexans put completion of the seabed surveys at the front of the revised work program.
Republic of Cyprus Energy Minister Michalis Damianos said on Aug. 19 that a French vessel would conduct the next survey phase once a new Navigational Telex (NAVTEX) was issued. Bosphorus News reported at the time that preparations were under way for a return off Kasos.
The unfinished work takes the project back to the Kasos-Karpathos area, where Greek and Turkish maritime jurisdiction claims collided during the 2024 survey campaign.
Mitsotakis has continued to say Greece is prepared to discuss with Türkiye only the delimitation of the continental shelf and exclusive economic zone in the Aegean and Eastern Mediterranean, a position he repeated in August.
Drone Restrictions Reported Over the Same Area
Ta Nea reported on Sept. 12 that six Greek NOTAMs establish Temporary Restricted Areas for unmanned aircraft around Karpathos, Kasos, Saria and Armathia from Sept. 16 through Oct. 31. The newspaper said the notices were issued on Sept. 9, the day Mitsotakis met Macron in Paris, and the following day.
According to Ta Nea, the restrictions apply daily from 7 a.m. to 7 p.m. and extend from ground level to 400 feet. The reported areas include Olympos, Aperi and Arkasa on Karpathos, all of Kasos and airspace around the two islands' airports.
The newspaper also reported that the notices do not identify the state agency responsible for the activity. An authorized state operator is to remain in contact with air traffic control during operations, with flights halted when required for aviation safety.
No official source reviewed by Bosphorus News has publicly connected the reported restrictions to GSI. The dates and geography overlap with preparations for renewed seabed work, but that does not establish a link between the two.
What Greece's Drone System Shows
Bosphorus News checked Greece's official Drone Aware Greece (DAGR) platform on Sept. 14, setting the public map to Sept. 16 and Sept. 17.
The six temporary areas reported by Ta Nea did not appear as separately identifiable restrictions around Karpathos or Kasos in the public view tested.
DAGR instead returned the established permanent limitations around the two airports. Around Karpathos, the system showed the Karpathos aerodrome traffic zone, registration r10000544, and the LGKP aerodrome perimeter, r10001169. Around Kasos, it showed the Kassos aerodrome traffic zone, r10000538, and the LGKS aerodrome perimeter, r10001165.
DAGR does carry restricted airspace categories. In the same regional view, Bosphorus News could see Hellenic Civil Aviation Authority Controlled Firing Areas r10000669 and r10000666, as well as Restricted Area r10000660. The platform also has dedicated layers for restricted, danger, prohibited and controlled firing areas.
Hellenic Civil Aviation Authority guidance tells drone operators to consult DAGR before flying and repeat the check shortly before departure. It says flights are prohibited where the platform displays a restriction.
The Hellenic Aviation Service Provider also warns that DAGR's aeronautical data are not guaranteed to be precise and instructs users to check Aeronautical Information Publication data and NOTAMs through their official channels.
Bosphorus News could therefore verify only that the six temporary areas reported by Ta Nea were not visible in the public system operators are told to check on Sept. 16 and 17. That does not mean the reported NOTAMs do not exist.
Back to Kasos
In July 2024, the Italian-flagged Ievoli Relume conducted seabed surveys off Kasos and Karpathos while Turkish and Greek naval units deployed in the area. Türkiye maintained that part of the work concerned waters it considers part of its continental shelf and required coordination with Ankara.
Athens rejected that position. IPTO said the July survey segment was completed according to schedule. The maritime dispute remained unresolved and further seabed work on the project was still required.
The same jurisdiction dispute has already surfaced in other cable work. In May, a Turkish missile boat challenged the Panama-flagged Ocean Link during telecommunications cable work between Astypalaia and Kos. A Greek frigate responded by radio and the work continued.
The legal argument surfaced again this month when Greek MEP Nikolas Farantouris described waters around Kasos as European waters. European Commission answers examined by Bosphorus News showed that the European Union does not have competence to establish or delimit member states' maritime zones, a distinction examined in Bosphorus News' review of the Kasos argument.
GSI's status as an EU-backed project does not determine the Greek-Turkish maritime boundary.
Cyprus Financing Dispute Remains
Türkiye's maritime objection is not the project's only unresolved problem. Under the Cyprus-Greece framework adopted in 2024, the Cyprus Energy Regulatory Authority (CERA) set allowed revenue at €25 million a year for 2025-2029, with a five-year ceiling of €125 million and remaining eligible amounts recoverable after the interconnector enters operation. In July 2025, CERA recognized €82 million in investment expenditure submitted by IPTO and set €25 million as recoverable for that year. IPTO later challenged the €82 million figure, saying approximately €251 million in investment expenditure had been certified, while denying that it was demanding immediate payment of the full amount. The dispute concerns which costs are recognized and when they can be recovered, separately from Türkiye's objections to survey activity in contested waters.
The October Window
Kathimerini reported on Sept. 14 that seabed soundings are expected to resume sometime between late September and early November. Greece is expected to issue a NAVTEX, while France plans to notify nearby coastal states.
The six drone restrictions reported by Ta Nea are scheduled to expire on Oct. 31, placing most of their duration inside the expected survey window. No official source reviewed by Bosphorus News has linked the restrictions to the cable work.
In 2024, Ievoli Relume sailed under the Italian flag. The next phase is expected to use a French vessel, and Greek reporting says it will sail under the French flag. Turkish sources have separately said the flag state is the government they expect to contact Ankara before work in waters where Türkiye claims jurisdiction.
If the plan proceeds as reported, the next Kasos survey will return to the same unresolved maritime dispute, with France now expected to make the contact Ankara says should precede work in waters Türkiye claims.
Sources: Office of the Prime Minister of Greece, Hellenic Aviation Service Provider, Hellenic Civil Aviation Authority, Cyprus Energy Regulatory Authority, Republic of Cyprus Ministry of Energy, Commerce and Industry, Cyprus Broadcasting Corporation, Kathimerini, Ta Nea, Cyprus Mail, Bosphorus News review and reporting.