The application of international law to submarine cables began with the International Convention for the Protection of Submarine Telegraph Cables offsite link (Paris Convention). The Convention was concluded at Paris on March 14, 1884, ratified by the United States in 1885, and entered into force on May 1, 1888. It is currently in force for 36 States Parties offsite link, who are obligated by its terms to protect submarine cables. Article I states that the Paris Convention applies “outside territorial waters to all legally established submarine cables landed on the territories, colonies, or possessions of one or more of the High Contracting Parties.” (Emphasis added.) Thus, the Paris Convention protects certain submarine cables on the bed of the high seas. At the heart of this Convention are three provisions:

• Article II declares it “a punishable offense to break or injure a submarine cable, willfully or by culpable negligence, in such a manner as might interrupt or obstruct telegraphic communications, either wholly or partially.”
• Article IV provides that the owner of a cable who, “on laying or repairing his own cable, breaks or injures another cable, must bear the cost of repairing the breakage or injury,” without prejudice to the application of Article II of the Convention. 
• Article VII provides that “[o]wners of ships or vessels who can prove that they have sacrificed an anchor, a net, or other fishing gear in order to avoid injuring a submarine cable, shall receive compensation from the owner of the cable.”

When the officers of a warship or a ship specifically designated by a Party to the Paris Convention have reason to believe that another vessel has committed an infraction of the measures provided for by the Convention, those officers “may require the captain or master [of that vessel] to exhibit the official documents furnishing evidence of the nationality of said vessel” and prepare a report which must be transmitted to the vessel’s flag state for appropriate action, “whatever may be the nationality of said vessel.” Paris Convention Article X. The only publicly reported instance in which a party used this authority occurred in 1959 when personnel of the U.S.S. Roy O. Hale boarded a Soviet trawler suspected of breaking several submarine cables. Dept. of State Bull. Vol. XL, No. 1034 (April 20, 1959) at 555-558 offsite link. The Parties to the Paris Convention are expected to apply their domestic laws to prosecute persons under their jurisdiction who damage submarine cables either willfully or through “culpable negligence.” Paris Convention Article X. The latter concept refers to a failure to use the ordinary skill that the prudent seaman would have used in a similar situation. See L. Carter, et al., Submarine Cables and the Oceans: Connecting the World, UNEP-WCMC Biodiversity Series No. 31 (2009) at 26. offsite link Although the Paris Convention only addresses submarine cables that are “outside territorial waters,” its negotiators understood that coastal States would also have laws protecting submarine cables within their territorial waters.

In April 1958 in Geneva, the first United Nations Conference on the Law of the Sea opened four conventions for signature, two of which addressed the subject of submarine cables, by adopting and/or extending the provisions of the Paris Convention. The Geneva Convention on the High Seas (CHS), which declared as its purpose “to codify the rules of international law relating to the high seas,” affirmed the right of all States to lay submarine cables on the bed of the high seas, thus including not only telegraph cables but telephonic and high-voltage power cables. The focus of the CHS again was outside territorial waters. Article I of the CHS defined “high seas” as “all parts of the sea that are not included in the territorial sea or in the internal waters of a State.” CHS Article II declared the high seas to be open to all nations and provided that freedom of the high seas, which is to be exercised with reasonable regard for the interests of other States, includes, for both coastal and non-coastal States, the freedom to lay submarine cables. CHS Parties commit themselves to pursuing the same type of domestic legislative measures described in the Paris Convention. CHS Articles 27 and 28. Subject to the right to take reasonable measures for the exploration of the continental shelf and the exploitation of its natural resources, a coastal State under the CHS may not impede the laying and maintenance of cables on the continental shelf. CHS Article 26. The latter provision was replicated in the Geneva Convention on the Continental Shelf 1958 offsite link (CCS). CCS Article 4. The United States ratified both the CHS and the CCS in 1961. UN Treaties Collection offsite link.

The 1982 United Nations Convention on the Law of the Sea offsite link (UNCLOS), to which the United States is not yet a party, incorporates the submarine cable protections of the CHS and CCS and clarifies other relevant matters. However, UNCLOS does not incorporate certain provisions of the Paris Convention, such as the references to civil liability for cable breakages and provisions allowing the boarding and inspection at sea of vessels suspected of willful or negligent damage to cables.

Under UNCLOS Article 2 offsite link, the sovereignty of a coastal State extends beyond its land territory and internal waters to an adjacent band of sea called the “territorial sea.”  The breadth of that territorial sea may not exceed 12 nautical miles, measured from baselines determined in accordance with UNCLOS. Article 3 offsite link. A coastal State may adopt laws and regulations in conformity with UNCLOS and other rules of international law relating to innocent passage through the territorial sea with respect to such matters as the protection of submarine cables. UNCLOS Article 21 offsite link. Nothing in the UNCLOS provisions pertaining to the Continental Shelf affects the right of the coastal State to establish conditions for cables entering its territory or territorial sea or its jurisdiction over cables constructed or used in connection with the exploration of its continental shelf or exploitation of its resources or the operation of artificial islands, installations, and structures under its jurisdiction. UNCLOS Article 79.4 offsite link.  

The sovereignty of an archipelagic state offsite link extends to the waters enclosed by archipelagic baselines. UNCLOS Article 47 offsite link. These are described as archipelagic waters. UNCLOS Article 49 offsite link, Article 52 offsite link. The archipelagic State must respect existing submarine cables laid in archipelagic waters by other States prior to UNCLOS and pass through that State’s archipelagic waters without making a landfall. The archipelagic State must also permit the maintenance and replacement of such cables after receiving due notice. UNCLOS Article 51(2) offsite link.

Within a coastal State’s EEZ, UNCLOS guarantees to all States, subject to the relevant provisions of UNCLOS, freedom to lay submarine cables, as well as other freedoms related to the operation of those cables, with due regard to the rights and duties of the coastal State. UNCLOS Article 58 offsite link. While UNCLOS redefines the term “high seas” offsite link to exclude not only a State’s territorial sea and archipelagic waters but also its EEZ, it preserves the right of all States to lay submarine cables in the EEZ, UNCLOS Article 87(1)(c), offsite link subject to the coastal State’s right to take reasonable measures for the exploration of the continental shelf and the exploitation of its natural resources. Article 79(2) offsite link.

As noted, all States are entitled to lay submarine cables on the continental shelf in accordance with the provisions of UNCLOS Article 79.1 offsite link. Subject to the right to take reasonable measures for the exploration of the continental shelf and the exploitation of its natural resources, the coastal State may not impede the laying or maintenance of cables. UNCLOS Article 79.2 offsite link. Although UNCLOS Article 79 does not explicitly provide that the consent of the coastal State is required for the delineation of the course of a submarine cable on the continental shelf as it does for submarine pipelines in UNCLOS Article 79.3 offsite link, this omission does not preclude a coastal State from delineating the course of a submarine cable that traverses its continental shelf but does not enter its territorial sea. The travaux préparatoires of UNCLOS (and its predecessor agreements) make plain that Article 79.3 was not intended to limit a coastal State’s ability to control the course of a submarine cable as a reasonable measure under Article 79.2. The provision that became UNCLOS Article 79(2) was lifted, practically verbatim, from article 4 of the 1958 CCS. Article 4 of the CCS was the product of years of deliberation by the International Law Commission, which wrestled with “[t]he general problem … of reconciling exclusive coastal use of the seabed and subsoil for exploration and exploitation of its natural resources with the generally recognized right to lay and operate cables, commonly considered to be protected by the doctrine of freedom of the seas.” Myres S. McDougal & William T. Burke, The Public Order of the Oceans offsite link 704 (1962). The International Law Commission’s compromise solution, which effectively accommodated these dissonant interests, was the “reasonable measures” language incorporated wholesale into UNCLOS Article 79(2). See id offsite link. at 705; see also Rep. of the Int’l Law Comm’n to the General Assembly, art. 61(2), 8th sess. April 23–July 4, 1956, U.N. Doc. A/3159 offsite link: GAOR, 11th Sess., Supp. No. 9 (1956) (including the International Law Commission’s “reasonable measures” language in an early UNCLOS draft). The International Law Commission made plain, in its commentary on the inclusion of the “reasonable measures” provision set forth in the early model for UNCLOS, that:

•  [The “reasonable measures” language] was added to make it quite clear that the coastal State is obliged to permit the laying of cables and pipelines on the floor of its continental shelf, but that it can impose conditions as to the route to be followed, in order to prevent undue interference with the exploitation of the natural resources of the seabed and subsoil. Clearly, cables and pipelines must not be laid in such a way as to hamper navigation.

Id., art. 61(3) cmt (emphasis added). See also id., art. 70 cmt; 2 offsite linkUnited Nations Convention On The Law Of The Sea 1982: A Commentary offsite link 915 (Myron H. Nordquist, et al., eds. 1993) (citing the travaux préparatoires of the final UNCLOS that article 79(3)’s “limitation on the freedom of all States to lay pipelines (but not cables) on the continental shelf” was intended to be “consistent with [article 79(2)], which allows a coastal State to take reasonable measures for the prevention, reduction and control of pollution from pipelines.”) (emphasis added).

Finally, UNCLOS also enhances the 1958 CHS provisions regarding a State’s duty to adopt laws and regulations making the protection of submarine cables effective. UNCLOS Article 113 offsite link requires every State to adopt laws and regulations making it a “punishable offense” for ships or persons subject to its jurisdiction to break or injure a submarine cable beneath the high seas, either willfully or through culpable negligence. UNCLOS strengthens this provision by making it applicable to conduct “calculated or likely to result” in such breaking or injury, UNCLOS Article 113 offsite link, whereas under the Paris Convention, the sanction was not triggered until after the damage was done. Similarly, UNCLOS Article 114 offsite link requires every State to adopt laws and regulations to provide for reimbursement of persons whose cable was broken or injured by someone subject to that State’s jurisdiction. UNCLOS Article 115 offsite link requires every State to adopt laws requiring indemnification of owners of ships that can prove they sacrificed an anchor, a net, or fishing gear to avoid damage to a cable.

Last Updated April 15, 2024