This article examines the critical vulnerabilities of underwater infrastructure, particularly in the context of recent attacks in the Baltic Sea. It analyses the evolving threat landscape, evaluates the limitations of existing legal frameworks, and investigates innovative approaches to enhance resilience. Key findings include the need for a revised international legal framework to address the evolving threats to critical underwater infrastructure, enhanced international cooperation, and the importance of technological advancements such as the Estonian SEAWOLF project and Portuguese DUAL SINES. The study emphasises increased investment in resilience measures, including port infrastructure upgrades, and promoting sustainable practices like “Green Corridors”.