Turkey has issued another NAVTEX concerning survey operations by the research vessel KOBI RUEGG for the East to Med Data Corridor (EMC), a submarine telecommunications cable project linking Saudi Arabia and Greece, renewing questions over whether the vessel has sought authorisation from Ankara to conduct operations in areas of the Eastern Mediterranean that fall within the Greek continental shelf.

The dispute is particularly significant because another vessel, the Abeille Marengo, is expected to operate in a nearby area to carry out surveys for the planned electricity interconnection between Cyprus and Crete.

Greece and Turkey have exchanged a series of NAVTEX maritime notices over the KOBI RUEGG’s activities in recent days, reflecting their competing claims over maritime jurisdiction in the Eastern Mediterranean.

The first Turkish notice, NAVTEX 1032/26, was issued by the Antalya station, which claimed that the geophysical surveys had been “coordinated with and approved by the competent Turkish authorities” and were being conducted within Turkey’s continental shelf.

Greece responded immediately through the Heraklion station, issuing a counter-NAVTEX stating that much of the survey area lies within the Greek continental shelf under international law and Greek Law 4001/2011. Athens also stressed that the area falls within Greece’s responsibility for issuing navigational warnings.

On Thursday morning, the Heraklion station issued a further notice concerning the vessel’s surveys, using similar coordinates and reiterating that the operations involved areas of the Greek continental shelf.

However, late on Thursday, the Antalya station issued another counter-NAVTEX, numbered 1042/26, asserting that the Bahamas-flagged research vessel KOBI RUEGG was conducting geophysical surveys for cable systems “with the consent of the Republic of Türkiye, within the Turkish continental shelf in the Eastern Mediterranean”.

The Turkish notice again challenged the authority of the Heraklion station, describing it as unauthorised to issue warnings for the area. Ankara also maintained that its earlier NAVTEX 1032/26 remained valid and in force, adding that the Antalya station would continue issuing navigational warnings in the interests of maritime safety.

The competing notices have raised further questions about the circumstances under which the vessel is conducting its surveys and whether Turkish permission was sought or obtained for operations in areas claimed by Greece.

The EMC project is being developed by a consortium comprising Saudi Arabia’s Center3, which holds a 72.15% stake, Greece’s Public Power Corporation (PPC), with 25%, and Cyprus-based TTSA CY, with 2.84%.

What Turkey’s latest NAVTEX says

The latest Turkish notice, TURNHOS N/W 1042/26, sets out Ankara’s position in three points.

1. The Bahamas-flagged research vessel KOBI RUEGG (MMSI: 31100683, IMO: 9713753) is conducting geophysical survey operations for cable systems with the consent of the Republic of Türkiye, within what Ankara describes as the Turkish continental shelf in the Eastern Mediterranean.

Turkey states that the outer limits of this continental shelf were communicated to the United Nations in a letter dated 18 March 2020, under reference A/74/757.

2. The notice describes the Greek NAVTEX messages HA61-1337/26 and HA67-1343/26 as having been issued by an unauthorised station and containing unfounded claims within what Turkey considers its NAVTEX service area.

Ankara asserts that the Antalya NAVTEX station is the competent authority for issuing such messages in the area.

3. Turkey maintains that NAVTEX 1032/26, previously issued by Antalya Turk Radio, remains valid and in force. It adds that the Antalya station will continue issuing navigational warnings to ensure maritime safety.

The earlier Turkish NAVTEX issued on Tuesday

The dispute began earlier in the week when Turkey issued NAVTEX 1032/26, concerning geophysical survey operations for the EMC submarine cable system.

The notice stated that the surveys announced under navigational warning MA37-302/26 covered an area falling within Turkey’s claimed NAVTEX service area and continental shelf in the Eastern Mediterranean.

It further asserted that the activities had been coordinated with and approved by the competent Turkish authorities.

According to the notice, the KOBI RUEGG was scheduled to carry out geophysical surveys for the East to Med Data Corridor cable system from 21 October 2026 until further notice.

The surveys were to follow specified routes, with corridors extending 10 nautical miles in width, covering five nautical miles on either side of the central survey line.

The continuation of the NAVTEX exchange highlights the sensitivity surrounding subsea infrastructure projects in the Eastern Mediterranean, particularly as preparations move forward for survey operations associated with the Cyprus-Crete electricity interconnection.