Menu

Ireland's sailing, boating & maritime magazine

RBC Brewin Dolphin proudly supporting Afloat and Irish Boating

Marine Notice: Geophysical Cable Condition Survey for East West Interconnector

14th October 2026
Green Rebel’s MV Roman Rebel will be engaged in offshore survey operations in the Irish Sea during the first half of November
Green Rebel’s MV Roman Rebel will be engaged in offshore survey operations in the Irish Sea during the first half of November

The Department of Transport advises that Green Rebel is undertaking nearshore and offshore survey operations on behalf of ACSM and EirGrid off the coast of Rush in north Co Dublin.

These survey operations will consist of hydrographic and geophysical works on the route of the East-West Interconnector undersea cable and will include towed operations (side-scan sonar).

Operations were scheduled to commence on Monday 12 October for the nearshore, followed by the offshore survey on Sunday 1 November, with an estimated completion date of Sunday 15 November, subject to weather and operational constraints.

Nearshore operations will take place north of Dublin, near Rush. These operations will extend from shallow water out to near the 30m bathymetric contour. Nearshore operations will also take place north of Wales, near Prestatyn.

Offshore operations will take place from the 30m bathymetric contour and move eastward across the Irish Sea into UK waters.

The survey will be conducted by the MV Lady Kathleen (nearshore; callsign EIXT2) and MV Roman Rebel (offshore, callsign 2ICA5). These vessels will display appropriate lights and markers and will have restricted manoeuvrability while towing equipment. The vessels will be listening on VHF Channel 16 throughout the course of the survey.

Coordinates and a map of the survey areas, as well as contact details, can be found in Marine Notice No 49 of 2026 attached below.

Downloads

Published in Undersea Cables
Afloat.ie Team

About The Author

Afloat.ie Team

Email The Author

Afloat.ie is Ireland's dedicated marine journalism team.

Have you got a story for our reporters? Email us here.

We've got a favour to ask

More people are reading Afloat.ie than ever thanks to the power of the internet but we're in stormy seas because advertising revenues across the media are falling fast. Unlike many news sites, we haven't put up a paywall because we want to keep our marine journalism open.

Afloat.ie is Ireland's only full-time marine journalism team and it takes time, money and hard work to produce our content.

So you can see why we need to ask for your help.

If everyone chipped in, we can enhance our coverage and our future would be more secure. You can help us through a small donation. Thank you.

Direct Donation to Afloat button

Undersea Cables

Undersea cables are vital to Ireland's connectivity, facilitating high-speed internet, telecommunications, and energy transmission. These cables traverse the Irish Sea, connecting Ireland to the United Kingdom and continental Europe, and play a crucial role in global communications.

Submarine Communications Cables:
Ireland is strategically positioned along major transatlantic communication routes. Approximately 75% of transatlantic cables pass near Irish waters, underscoring the nation's significance in global data transmission.
These cables are typically as wide as a garden hose, with the filaments that carry light signals being extremely thin—roughly the diameter of a human hair. They are sheathed in layers of insulation and protection, with cables laid nearer to shore using extra layers of armoring for enhanced protection.

Energy Interconnectors:
In addition to communication cables, undersea interconnectors are being developed to enhance energy security and support the transition to renewable energy sources. The UK has approved the construction of five new subsea interconnector cables to boost the grid's flexibility amidst rising renewable energy. These projects will link the UK with wind farms in Belgium and the Netherlands, and connect England with Germany, Wales with Ireland, and Scotland with Northern Ireland. The cables, with a combined 6GW capacity, are expected to be operational by 2032, increasing the UK's total interconnector capacity to 18GW.

Security Concerns:
The strategic importance of these undersea cables has raised security concerns. Incidents in the Baltics have heightened awareness about the potential risks to subsea infrastructure. Ireland's historical neutrality and limited defense resources have led to calls for enhanced maritime security and defense investments, including modern surveillance technology and international cooperation. The government's response includes participation in EU security projects and collaboration with neighboring countries on maritime security.

In November 2024, a Russian spy ship, the Yantar, was escorted out of the Irish Sea by the Irish navy after it was found patrolling an area with critical submarine pipelines and cables. The vessel's presence heightened concerns due to its proximity to interconnector cables vital for internet services linking Ireland to the UK, operated by major tech companies such as Google and Microsoft.

Regulatory and Policy Framework:
The protection and maintenance of undersea cables fall under the jurisdiction of national governments, with private companies often responsible for their security. In Ireland, the Department of Communications, Climate Action and Environment oversees the regulation of telecommunications infrastructure, including undersea cables. The Irish Naval Service plays a role in monitoring and protecting maritime infrastructure, including undersea cables. Internationally, the United Nations Convention on the Law of the Sea (UNCLOS) provides a framework for the laying and maintenance of submarine cables, recognizing the "freedom of the seas" and the rights of coastal states.

Conclusion:
Undersea cables are indispensable to Ireland's connectivity and economic infrastructure. Given their strategic importance, ongoing efforts are necessary to ensure their protection and resilience against potential threats. This includes enhancing security measures, international cooperation, and adherence to regulatory frameworks to safeguard these critical assets.