Turkey’s Piri Reis vessel to conduct Aegean surveys under NAVTEX, raising tensions with Greece. Credit: Mehmet Ozdogru/ Anatolian Agency/ EPA via AMNA
Greece and Turkey are once again at odds in the Aegean after Ankara issued a NAVTEX announcing that its oceanographic vessel Piri Reis will conduct scientific surveys over the next ten days. The notice, broadcast as NAVTEX 0863/25 by Turkey’s Izmir station, outlines a research route stretching west of Lesvos, south of Chios, and toward the islet of Kalogeros—located between Chios and Andros.
A NAVTEX (NAVigational TEleX) is an international automated system for broadcasting urgent maritime safety information to ships.
Although the Piri Reis is technically capable of carrying out such research, the move immediately raises questions of jurisdiction. Parts of the vessel’s declared route pass through Greek territorial waters and over Greece’s continental shelf—areas where Turkey lacks authority to issue NAVTEX.
The Kalogeros segment of the mission carries additional symbolism: the islet lies within a permanent Greek military firing range, making its inclusion in the survey route a pointed reminder of Ankara’s longstanding objections to Greek defense activities in the area.
Athens reacted swiftly with a counter-NAVTEX (154/25 issued by the Lemnos station), challenging Turkey’s jurisdiction and signaling that Greek authorities will closely monitor the Piri Reis both diplomatically and at sea.
Why Turkey issued the NAVTEX which has alarmed Greece
While framed as a scientific mission, Ankara’s NAVTEX serves a broader geopolitical purpose. By asserting a role in central Aegean waters, Turkey is signaling its refusal to accept Greece’s interpretation of maritime zones.
At the same time, the move coincides with two sensitive developments: the submission of an energy exploration bid by US energy giant Chevron for offshore blocks south of Crete, and renewed momentum on the Greece–Cyprus electricity interconnection project. Both initiatives strengthen Athens’ position in the Eastern Mediterranean energy landscape—an area where Ankara seeks influence and leverage.
Thus, beyond oceanographic surveys, Turkey’s NAVTEX is intended as a strategic message. It is a reminder that Ankara remains a stakeholder in the region’s maritime and energy future and that it will contest any Greek moves perceived as sidelining Turkish interests.