French research vessel deploys for Great Sea Interconnector amid Aegean diplomatic friction

On November 10, 2026, the French research vessel Abeille Marengo departed the port of Heraklion, Crete, to conduct seabed mapping for the Great Sea Interconnector (GSI) electricity cable project, which aims to link the grids of Greece and Cyprus. Before entering the designated search area south of Kassos and Karpathos, the ship began equipment calibration tests. The project is being managed under authorizations granted solely by Greek and Cypriot authorities.

Following the departure, Turkey issued a NAVTEX (1127/26) claiming the vessel's operations were occurring within the Turkish continental shelf and required Turkish consent. Ankara asserted that it had coordinated and authorized the research. In response, the Greek Ministry of Foreign Affairs and official diplomatic sources dismissed the Turkish claims as irrelevant, emphasizing that no requests were submitted to Ankara. Early on November 11, Greece issued a formal anti-NAVTEX, declaring the Turkish notice invalid and asserting that the survey area falls within the Greek Exclusive Economic Zone and continental shelf.

While the vessel continues its mission, the situation remains a focal point of regional geopolitical tensions. The research is scheduled to continue through March 2027, as both sides maintain their respective positions on sovereignty and maritime jurisdiction in the Eastern Mediterranean.