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Indian Ocean's Submarine Cables

Updated: Oct 9, 2023

Data is the driver of trade deals and personal communication. Every day, multi-billion-dollar worth of trade passes through the routes of the Indo-Pacific via subsea cables. This has caused a growing worldwide concern over the protection of subsea cables in the Indian Ocean. The region has gained economic and political momentum in the last few years, and this further validates the concern to protect data transmission worldwide.

Indian Ocean's Submarine Cables

Image Graphics by Team Geostrata

What are submarine cables?

Submarine or subsea cables are essentially optic fibre wires that are laid on ocean or sea beds to connect two landmasses’ populations separated by the sea. While the actual wire through which data signals travel is as thin as a hair strand, the whole system usually has a girth equal to that of a garden hose due to the layers of nylon, plastic, steel, and copper, further protected by silicon gel.

The whole system starts at the station where the armoured cable originates and hosts the data packets for the first time. It then converts into the unarmoured cable as it proceeds deeper into the water body, carrying the packets further. The system is affixed by repeaters or amplifiers at regular distances, which boost the connectivity of data packets and speed up the transmission process. It finally ends at the landing station, where the data signal is received and deciphered.

The whole process sounds far-fetched, quite literally, but it only takes a few seconds. Each hair-like fibre can transmit data at a speed of approx. 4000 GB per second, and every cable contains around 200 such wires. Each wire is, thus, responsible for more than a billion phone calls per day.

What are their functions?

As mentioned above, these cables are mostly used for data and communication transfers. But this is exactly what drives our socio-economic reality. Since India’s Liberalisation, Privatisation, and Globalisation (LPG) phase, the scope for attracting foreign investments and jobs under KPO has largely increased. For every hour of the functioning of such wires, a million dollars worth of transmission controls the lives of employees and projects far and wide.

These are especially important for private firms and businesses because they connect companies abroad via the Internet, and without them there would be no communication, meaning no deals. Companies working specifically in the IT sector face losses since their whole edifice is ICT. Subsea cables can carry higher loads faster during rush hour and are, hence, more favourable for cloud computing, satellite transmission, etc.

Several private and non-private companies have set up submarine telecommunication cables. For example, in the SEA-ME-WE 4 cable system, Bharti Airtel and Tata Communications Ltd. are consortium members.

While TCL owns its Mumbai landing station, the former owns the other one in Chennai. According to data, 97% of India’s global transmission is carried by approximately 545,018 miles of fibre. The extent of the loss that could be faced directly by India, and indirectly by the world due to the stagnation of these wires is unimaginable.

How are they under threat?

In natural situations, the wire can be damaged by marine fauna or fishing activities. For example, there have been cases of sharks biting the cable, which might cause damage, but these cases are rare. Apart from this, natural disasters such as tsunamis, volcano eruptions, cyclones, etc. also pose a challenge.

Major activities that can cause damage are caused by human activities, which can be innocent or deliberate. Fishing and commercial activities, including offshore oil and gas developments, take place near the landing stations. These activities happening in proximity to the cables make them vulnerable to being severed, causing a “fault”, which means that the cable is pulled apart.

In 2008, the disruption of undersea cables in Egypt and Dubai caused India a loss of 80% of international services over two weeks. In more recent times, the example of three Nord Stream 1 and 2 pipelines in the Baltic region being damaged suspiciously due to TNT blasts in the vicinity are a perfect example of how warring countries might use this technique on purpose.

What has the government done?

Not many governments have a proper definition of what submarine cables entail, and neither does India, in the Constitution or any formal sense. There is a mention of undersea communication cables in the Constitution by The Indian Telegraph Act, 1885, and that’s it. This establishes that there is no clear indication of what threats the cable systems might face or how these can be mitigated by the government or anyone else.

So, while there is no particular legislation owing to the issue of protecting the cables, there is an additional problem of jurisdiction. Article 21(c) of the UNCLOS lays down guidelines to protect these cables, but it does not define responsibility and accountability for damage in international waters. Does it belong to the private firm, the government of the source station, or that of the landing station, or does it belong to the overarching multilateral authorities? There is no idea. The governments of some countries, like Australia and New Zealand, have established clear directions on the matter of subsea cables, but to a narrow extent.

How can they be protected?

India needs a strong and resilient warning system to detect any potential threats around the cable systems that fall under its territory. But primarily, stress should be placed on formalising the legislation on undersea cables and their protection. This is because even though the UNCLOS sets provisions for the protection of sea cables, it can do so only on the High Seas and in a normative manner.

India should, thus, establish a separate institution to look after the legislation that the government brings about with the help of Working Groups, scientists, and the local people in coastal areas. There should be set rules for fishing and mining activities by private companies and local people, maintaining equal treatment for both.

Cable Protection Zones can be created, taking inspiration from New Zealand, that demarcate the cable territory, along with guidelines for punishing the offender. Most importantly, the Indian Navy should help protect the zones and be vigilant in terms of innocent fishermen or people with malicious intent.

In terms of domestic legislation too, the Telecom Regulatory Authority of India has issued a report on the ‘Licencing Framework and Regulatory Mechanism for Submarine Cable Landing in India’. The Department of Telecom (DoT) is working with TRAI to come up with a legal framework that would secure public and government data transmission.

The subsea cable systems should be made a part of the Critical Information Infrastructure of India while enabling the extra-territorial implementation of this Indian law. The latter would require a cooperative effort on the part of all countries in the Indian Ocean Region so that laws relating to this field align with each other. This cooperation should not limit itself to governments but expand to include a plethora of stakeholders, such as private companies, local groups, think tanks, and maritime strategic research organisations.


It is a multilateral world, and no country can unilaterally pass laws relating to something that concerns everyone. Submarine cables in the IOR not only affect India or neighbouring island countries but also affect the functioning and economy of related entities. Multilateral problems need multilateral solutions. It is time that an example is set by the international community that cooperation is not an impossibility, and the trailblazer of this example can be the ratification of common laws in international waters for the protection of data links that run the world.




1 Comment

very informative!

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