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Marine Notice: Geophysical and Geotechnical Survey off Galway Coast

27th October 2025
File image of the survey vessel Explora
The survey will be conducted in the Atlantic Ocean off Co Galway by the Explora until mid December Credit: Wikimedia

The Department of Transport advises that a geophysical and geotechnical survey is being undertaken by Elettra TLC SpA in the Atlantic Ocean off the coast of Co Galway on behalf of Deepsea Fibre Networks Ltd.

This survey involves the deployment of towed equipment within the bounds of the survey area between Sunday 26 October and Thursday 11 December, depending on weather and operational constraints.

The survey will be conducted by the Explora (callsign IXWQ) which will display appropriate lights and signals. Due to the deployment of towed survey equipment for the duration of the survey activities, the survey vessel will be restricted in its ability to manoeuvre and as such other vessels are kindly requested to keep a wide berth.

Vessels are requested to pass at a safe speed and distance and fishing vessels in particular are advised to remain a safe distance from the survey area.

The Explora will maintain a listening watch on VHF Channel 16. Mariners are advised to keep continuous watch when navigating the area. A marine and fisheries liaison officer will be available to discuss operations throughout the survey campaign.

Coordinates and a map of the survey area, as well as contact details, can be found in Marine Notice No 57 of 2025 attached below.

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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.