Introduction
In the London market, the activities of the so-called “Russian shadow fleet” continue to attract significant attention - particularly following reports that armed Russian naval vessels have begun escorting sanctioned ships through the English Channel. This substantial number of aging tankers and cargo vessels continue to operate under false flags, with obscured ownership and the use of location spoofing techniques to evade detection. The aim of some “dark vessels”, however, may not be limited to avoiding sanctions against Russia, but by, quite literally, dropping the anchor, they may also cause you some connectivity issues.Approximately one million miles of submarine cables currently in service worldwide are responsible for transmitting 99% of global intercontinental internet traffic. In parallel, thousands of submarine pipelines play a critical role in the transportation of energy resources. Given the strategic importance of this infrastructure, it is unsurprising that any incident affecting these systems could trigger a cascading impact affecting both economic and military capabilities.
Recent events
Given the critical importance of this infrastructure, it may come as a surprise that the majority of submarine cables are not buried beneath the seabed. While burial is common near shorelines, most cables are instead laid directly on the seabed, leaving them susceptible not only to accidental damage but also to deliberate interference or sabotage.
Recent incidents in regions such as the Baltic Sea, but also the Red Sea and the Taiwan Strait, have underscored these vulnerabilities. Notably, the Nord Stream 1 and Nord Stream 2 gas pipeline incidents have drawn significant attention. Although investigations into these events remain ongoing, it is important to note that damage to submarine cables occurs with regularity and continues to pose a substantial risk to global infrastructure.
While NATO’s Allied Maritime Command (MARCOM), based on the outskirts of London, plays a key role in coordinating protective measures for submarine cables and pipelines, these efforts are also supported by an established legal framework, which is further addressed below.
Legal framework
3.1 The 1884 Paris Convention for the Protection of Submarine Telegraph Cables (“Paris Convention”)
Perhaps unexpectedly, the first international convention addressing submarine infrastructure dates back to 1884, with the adoption of the Paris Convention for the Protection of Submarine Telegraph Cables. This treaty establishes, among other provisions, that the intentional or negligent breaking or damaging of a submarine cable constitutes a punishable offence and may give rise to civil action for damages.
An exception to this rule applies where the damage results from lawful efforts to save lives or a vessel in distress, provided that all necessary precautions were taken to avoid such damage. Conversely, vessel owners who can demonstrate that they have sacrificed an anchor, net, or other fishing gear in order to prevent harm to a submarine cable are entitled to compensation from the cable owner.
That said, the contemporary relevance of the Paris Convention is limited. As its title suggests, the Convention pertains specifically to telegraph cables – technology that is now largely obsolete.
3.2 The 1982 United Nations Convention on the Law of the Sea (UNCLOS)
A more pertinent legal framework for assessing recent incidents involving submarine infrastructure is the 1982 United Nations Convention on the Law of the Sea (UNCLOS).
Under the Convention, vessels are in principle entitled to the right of innocent passage through a State’s waters, including territorial waters. However, this right is subject to specific conditions and limitations.
Article 19 of UNCLOS codifies the definition of “innocent passage,” stipulating that:
"Passage is innocent so long as it is not prejudicial to the peace, good order or security of the coastal State. Such passage shall take place in conformity with this Convention and with other rules of international law."
As an exception to this right of, otherwise innocent, passage, states are entitled to adopt and enforce legislation that protects their submarine cables and potentially affects the passage of other vessels. In addition, pursuant to the principle of sovereignty, coastal States may exercise criminal jurisdiction within their territorial sea, albeit subject to certain conditions.
A recent illustration of a State asserting such jurisdiction involves the vessel EAGLE S, which allegedly severed a telecommunications cable between Finland and Sweden by dragging its anchor along the seabed. The vessel’s owners contested the Finnish authorities’ actions on the basis that the incident occurred outside Finnish territorial waters. Nevertheless, the Finnish courts upheld the seizure of the vessel until March 2025.
Following the investigation, Finnish prosecutors are reportedly considering criminal charges against three senior officers. Given that States are entitled to lay submarine cables not only within their territorial waters but also within their exclusive economic zones (EEZ), continental shelves, and on the high seas, a pertinent legal question arises: do States possess adequate legal mechanisms to prosecute individuals responsible for damaging such infrastructure beyond their territorial waters?
This question is addressed in Article 113 (UNCLOS), which obliges Signatories to establish jurisdiction over offences involving the intentional or negligent damage of submarine cables by vessels flying their flag, or by persons subject to its jurisdiction. Accordingly, the article does not, in itself, establish a basis for liability, impose penalties, or mandate the imposition of penalties for damage to submarine cables.
Rather, it serves to confer jurisdiction upon States to prosecute such offences. Given the self-prosecute nature of this rule, the practical enforcement of this provision is limited, particularly in jurisdictions where the political will or legal infrastructure to pursue such prosecutions is lacking. Deterrence by NATO could very well be the only effective measure in case of state sabotage.
Civil claims in practice
In practice, when a submarine cable is damaged by a vessel, it is typically incumbent upon the cable owner to initiate legal proceedings to recover damages.
Where the defendant is domiciled in the United Kingdom or has agreed to submit to the jurisdiction of the UK courts (or arbitration), proceedings may be brought domestically. However, in cases involving defendants domiciled within the European Union, the Brussels I Recast Regulation (Regulation (EU) No 1215/2012) would apply. As a general rule under this Regulation, a defendant can be sued in the courts of the Member State in which they are domiciled. Alternatively, UK courts may assume jurisdiction over an EU-based defendant if the damage occurred within UK territorial waters.
Vessel owners may seek to limit their liability pursuant to the Convention on Limitation of Liability for Maritime Claims (LLMC), which has been incorporated into English law. The applicable liability cap is calculated based on the vessel’s gross tonnage. However, in the case of smaller vessels - such as fishing boats operating in the Channel or Baltic Sea - this cap may prove significantly inadequate to cover the full extent of the damage caused. Only when intent to cause damage can be proven, which would be a hard task, will the vessel owner be unable to rely on the limitation of liability.
It is also worth noting that when a submarine cable is not buried beneath the seabed - particularly as burial is typically limited to nearshore areas - has not, in itself been found to constitute contributory negligence on the part of the cable owner. Accordingly, it is incumbent upon vessel operators to conduct at least a reasonable level of due diligence regarding the waters in which they navigate, including the potential presence of submarine cables.
Insurance implications
It is reported that between 75 and 100 incidents involving submarine cables are attributed to fishing vessels each year, accounting for approximately two-thirds of all such incidents. In most cases, vessel owners are able to rely on protection and indemnity (P&I) club insurance to cover liability claims brought by third parties.
However, the financial exposure resulting from damage to submarine cables can be substantial. The cost of repairing a single telecommunications cable may exceed GBP 1,000,000, and in some cases, total losses - including service disruption and associated claims - have been reported to reach as high as GBP 100,000,000. In the event of an internet or electricity blackout, affected businesses on shore may also seek compensation under their own insurance policies for business interruption, potentially triggering a cascade of claims across the insurance market.
Although the majority of incidents are linked to fishing activity, recent acts of sabotage have drawn renewed attention and concern to the broader vulnerabilities of submarine infrastructure. As a result, insurers may increasingly consider adjusting premium structures, both for vessel owners and for operators of submarine cables. This may be particularly relevant for vessels operating exclusively in areas with dense cable networks. Moreover, it is not unimaginable that vessel owners will have to demonstrate to insurers that the crew on the vessel has had sufficient training to sail through sensitive areas.
That is for those not operating in the shadows.
Stay connected and please do reach out if you have any queries in relation to this article.
