Damage caused to underwater infrastructure has increased in frequency over the past few years. Incidents in the North Sea and the Baltic Sea have shown that anchor-dragging ships can easily cause disruption to internet or electrical networks, along with examples of other methods of deliberate harm, such as the use of explosives. The main legal challenges to the protection of critical offshore infrastructure lie outside the limits of the territorial sea. Relevant treaty law grants stronger legal protections to wrecks, unmanned platforms and floating buoys than to cross-border submarine telecommunications and power cables or gas and oil pipelines. Whilst the legal framework is fragmented and contains significant gaps, the United Nations Convention on the Law of the Sea permits coastal States to enforce their laws for the protection of submarine cables and pipelines outside the territorial sea. Based on the effects doctrine and the protective principle, coastal States can extend their criminal jurisdiction over deliberate damage to submarine cables and pipelines connected to their territory. Furthermore, recent incidents in Europe show that suspected stateless ships can be interdicted by the coastal State.