Diplomatic tension in the Mediterranean over Great Sea Interconnector research

The French research vessel Abeille Marengo departed from Heraklion, Crete, on November 10, 2026, to conduct bathymetric surveys for the Great Sea Interconnector (GSI) power project. The mission, intended to link the power grids of Greece and Cyprus, immediately sparked diplomatic friction after Turkish authorities issued a NAVTEX (1127/26) claiming that the research is being conducted within the Turkish continental shelf and with their consent. Turkish authorities further referenced a 2020 UN letter to support their jurisdictional claims in the area.

In response, Greek and Cypriot authorities dismissed the Turkish assertions as invalid. Athens and Nicosia emphasized that they are the only countries to which permit requests were submitted and subsequently approved. On November 11, Greece issued a counter-NAVTEX declaring the Turkish notification illegitimate, noting that the Greek hydrographic station in Heraklion maintains exclusive authority over the region. Cyprus followed with its own anti-NAVTEX, affirming that the survey operations strictly fall under its authorized maritime jurisdiction. The Abeille Marengo is currently proceeding with equipment calibration near the islands of Kasos and Karpathos to continue its technical mission under the authority of Greek and Cypriot permits.