ABSTRACT Subsea infrastructure is typically out of sight, but in recent times, seldom out of mind. The sabotage of the Nord Stream pipelines in October 2022 has magnified the vulnerability and critical importance of subsea infrastructure. It also exposed a lack of understanding on how subsea networks operate, how they are regulated, who controls them and how they are protected. Ireland matters in this context. Despite its official policy of neutrality, Ireland occupies an important strategic position in terms of transatlantic telecommunications cables between the United States, Britain and continental Europe. The conflict in Ukraine has amplified tensions in this context in terms of the increased threat of grey-zone/hybrid warfare activity. This article will consider for the first time how a global connectivity hub on the western periphery of Europe governs critical underwater infrastructure. It will discuss the context and agencies involved in subsea cable governance in Ireland and identify the gaps in this protection before formulating suggestions for the long-term improvement of Ireland’s maritime security capacity. The Irish case is important as it can help inform defence policy and security practice in other island states with large maritime jurisdictions and in particular states with small navies.