The Legal Status and Applicable Regime of International Submarine Cables

By Marta Lahuerta Escolano
May 18, 2022

As published in the May Issue of SubTel Forum Magazine


The submarine fiber optic cable networks are a true “bridge between people” and are part of the international infrastructures that are unique due to their technical nature, their vital importance for the economy and national security and their vulnerability.

According to the International Telecommunications Union, a submarine communications cable is “a cable laid in the sea bed, or buried in shallow water, intended to carry communications”[1]. Submarine cables use fiber optics to transmit data at the speed of light.

Just over 420 cables are buried in the depths of the world's oceans and provide 99% of the world's communications via telephone exchanges and Internet access[2].

Despite the successful installation of the first submarine cable in the 19th century, little is known about these infrastructures and several legal issues remain regarding their legal status and the regime governing their construction, installation and landing.

A submarine cable crosses multiple environments: land or sea, on the one hand, and cyber or physical space, on the other. This heterogeneity of environments encountered by the submarine cable network is materialized by a dispersed legal framework[3].

International law

The international nature of submarine cables, which often link several States (for example, the 2 AFRICA submarine cable extends over 45,000 km and is intended to link 33 countries), creates legal difficulties at many levels.

In addition, to the question of the rights conferred and the obligations imposed on the suppliers, owners and installers of cables crossing several States, there is also the question of the protection of these critical infrastructures.

United Nations Convention on the Law of the Sea

Most of the international law applicable to the laying of submarine cables comes from the United Nations Convention on the Law of the Sea (Montego Bay Convention of December 10, 1982). It incorporates and completes the essential provisions of the Paris Convention of 1884 on the protection of submarine cables and the Geneva Convention of 1958 on the Law of the Sea.

The Montego Bay Convention provides a legal division of the sea into several maritime spaces, the applicable international legal regime being different in each of these spaces.

According to article 3 of the Montego Bay Convention, the territorial sea borders the coasts of States and can extend up to 12 nautical miles beyond the baselines. The territorial sea is an integral part of the sovereign territory of States. Consequently, the coastal State has the right to legislate and regulate the deployment of cables in this area. The laying of submarine cables in the territorial sea is often subject to an administrative authorization from the competent authority for the use of the public maritime domain. At the very least, coastal States require a formal application for the laying of a submarine cable issued by the installer with the assistance of the owner of the submarine cable. This authorization may also be accompanied by the payment of a tax or fee. In some countries, the fee applicable to submarine cables laid in waters under the sovereignty of a country, is established per linear meter of cable.

Beyond the territorial sea, articles 58.1 and 79.1 of the Montego Bay Convention establish a principle of freedom according to which all States have the right to lay submarine cables on the continental shelf[4] and in the exclusive economic zone (EEZ)[5]. However, this freedom remains subject to the powers reserved to the coastal State which may take reasonable measures to protect its artificial islands, structures and installations deployed in these areas or to guarantee the exercise of its right to explore and exploit the continental shelf[6]. In principle, the coastal State should not require authorization for the laying of submarine cables in this area. However, it may request that the route of submarine cables in this zone be communicated to it. It may thus request its modification if necessary. Consequently, in this zone, the laying of cables is free, taking into account the rights and obligations of the coastal State[7].

The freedom to lay submarine cables is only complete on the high seas or in international waters (all the maritime space that extends beyond the EEZ and the continental shelf)[8] where all States, coastal or not, have “the freedom to lay submarine cables and pipelines”[9].

The international sources of law applicable to submarine cables are supplemented by a set of regional, bilateral and multilateral sources.

Regional law

Regional organizations have taken an interest in the supervision of submarine cables by formulating guidelines and directives for their member states. This is the case of the Economic Community of West African States (ECOWAS) which, through a 2012 regulation[10], adopted a set of rules setting out the conditions of access to submarine cable landing stations. Thus, in its article 4.1, the regulation requires Member States to encourage the granting of licenses to new submarine cable landing stations. In order to promote equitable access to bandwidth, Member States must ensure that, when granting licenses to operators, they include provisions on open access to cable landing stations and on the provision of international capacity on a non-discriminatory basis.

Some bilateral and multilateral agreements

Some bilateral and multilateral agreements also organize the relations between States in terms of laying submarine cables. One example is the agreement concluded in 2009 between Estonia, Latvia, Lithuania and Sweden for the construction of a high voltage submarine cable under the Baltic Sea.

National Law

Multiple areas of law

Submarine cable networks are subject to international law, but are also governed by national legislation.

In the domestic order, sovereign States subject the laying, landing and operation of submarine cables to various legal regimes.

Submarine cables are thus governed by various areas of law, in particular, electronic communications law – since they are electronic communications networks -, public and real estate law – which determines in particular the rules applicable to the construction and occupation of the public maritime domain -, environmental law – which requires a certain number of studies to be carried out in order to assess, among other things, the impact on the environment and the environment, among other things, the impact on the environment and the marine environment of the submarine cable deployment project -, industrial property law – in order to protect the inventor's right -, cybersecurity law, defense law and criminal law – allowing the sanctioning of any behavior likely to cause deterioration of the network.

Today, national legislation on the laying of submarine cables is becoming increasingly flexible in order to provide the most attractive legal framework possible to encourage the installation of new submarine cables. In France, this trend is illustrated by the Circular issued by the Secretary General for the Sea on November 13, 2020, which aims to streamline administrative procedures for submarine communication cables by establishing a single point of contact in the administration.

This simplification effort is very welcome for international submarine cable project developers.

The complexity of a file is not only technical, negotiations can be long with governments and all stakeholders. Any initiative to facilitate the deployment of the cable will be taken into consideration by the cable owners to define the landing points.

Private law

The private owner of a submarine cable is often a single company, as it is the case of Google's Equiano submarine cable, or a consortium of companies, as it is the case of the 2 Africa, Africa-1 or ACE cables systems.

Submarine cable deployment projects entail a fairly complex contractual architecture, starting with the non-disclosure agreement (NDA), followed by the memorandum of understanding (MOU), the Joint Build Agreement (JBA) governing relations between the various entities forming part of a consortium, the construction and maintenance contract (C&MA) to be concluded between the supplier and the owner of the cable that establishes the sharing of the responsibilities between each of the parties, the Joint System Maintenance Document (JSMD) which explains the technical and safety aspects of the submarine cable, the branch construction contract, the Landing Agreement (LPA/LSA) to be concluded with the entity owning the landing station which determines the conditions of the co-location and operation and maintenance service and the agreements for crossings of other cables or pre-existing pipelines

Protection of cables

The protection of submarine cables results from a regime defined by the International Convention for the Protection of Submarine Cables signed in Paris in 1884. The Montego Bay Convention takes up some of these provisions and provides in particular for the obligation for States to sanction the deterioration or breaking of a cable.

However, the protection measures provided for in these texts are not sufficient in view of the threats and the critical importance of these infrastructures. Submarine cables have thus been targets in times of war.

The Paris Convention of 1884 allowed the belligerents freedom of action in wartime[11]. They could then cut submarine cables. Thus, during the Russo-Turkish war of 1877-1878, the Ottoman Empire proceeded to cut a cable between Constantinople and Odessa[12].

The Paris Convention offered protection to submarine cables only in non-wartime. This protection was taken over by the Montego Bay Convention. The International Cable Protection Committee established in 1958 continued this protection work by issuing international recommendations for the installation, protection and maintenance of cables.

In August 2014, Russia severed Ukrainian submarine cables during the annexation of Crimea. The intensity of the ongoing conflict between Ukraine and Russia and the threat of Russian occupation of Odessa, Ukraine's largest seaport, has reignited concerns about the risk of submarine cable severance.

In this context, it is essential to strengthen the legal framework protecting submarine cables. This will not be an easy task given the hybrid nature of this infrastructure, which can be used for both civilian and military purposes.

Marta Lahuerta Escolano is Counsel at Jones Day. Marta focuses on telecommunications, media and technologies (TMT). She has been admitted to the Paris and Madrid bar. Her practice covers all aspects related to the regulation of the sector, transactions, project financing and litigation.

She has recognized expertise in submarine cables, covering all contractual aspects related to the deployment of a submarine cable system project, from the conceptual phase to upgrades, including design, implementation, operation and maintenance. Her expertise also covers the drafting and negotiation of documentation related to the implementation of landing stations, the provision of landing services, co-location and access to terrestrial fibers.

Any views or opinions expressed in this article are personal and belong solely to the author.

[1] International Telecommunication Union, “Submarine Cable Regulation”, PowerPoint presentation, 2010, available online at:

[2] L'incroyable histoire des câbles sous-marins, des télégraphes à Internet, Les Echos, 7 October 2021.

[3] Camille Morel, L'Etat et le réseau mondial de câbles sous-marins de communication, PhD thesis in public law, Université Jean Moulin Lyon 3, defended on November 18, 2020.

[4] In accordance with article 76.1 of the Montego Bay Convention, the continental shelf comprises the seabed and subsoil beyond the territorial sea of the coastal State throughout the natural prolongation of the land territory of that State to the outer edge of the continental margin, or up to 200 nautical miles from the baselines from which the breadth of the territorial sea is measured, where the outer edge of the continental margin is less than that distance.

[5] According to articles 55 and 57 of the Montego Bay Convention, the exclusive economic zone (EEZ) is located beyond the territorial sea and extends to 200 nautical miles from the baselines.

[6] Except in this case, the coastal State must not hinder the laying or maintenance of submarine cables or pipelines (article 79. 2. of the Montego Bay Convention).

[7] JurisCalsseur Communications, Fasc. 400 : Droit international des télécommunications, 1st April 2021.

[8] Article 86 of the Montego Bay Convention.

[9] Articles 87 and 112 of the Montego Bay Convention.

[10] Council Regulation C/REG.06/06/12 on conditions of access to submarine cable landing stations. According to article 12.3 of the revised ECOWAS Treaty, ECOWAS Council Regulations are binding on Member States after their approval by the Conference.

[11] P. Achilleas, op. cit. n° 72 and following.

[12] C. Morel, The endangerment of the international submarine communication network, Flux 2019/4, n° 118, p.35 and following.

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