Singapore’s Subsea Cables

Introduction

Singapore is a critical hub for subsea cable networks in Southeast Asia, connecting the maritime and mainland countries to the rest of Asia, the Middle East, Europe, and North America. This role builds upon a long legacy dating back to the 1870s, when telegraph cables linked the city-state to Australia, Hong Kong, and India. Today, more than 99 percent of Singapore’s international telecommunications traffic is carried by subsea cables, making them essential for both its national security and its economy.

Southeast Asia’s demand for high-speed connectivity has been steadily growing, driven by expanding digital adoption, e-commerce, and cross-border data flows. In this context, Singapore’s geographic location, pro-business regulatory environment, and forward-looking digital policy and infrastructure planning have positioned it at the center of regional and global data movement. This has enabled it to attract significant investment from both regional telecom giants and global tech firms. Through its Digital Connectivity Blueprint, Singapore seeks to maintain its hub status and enhance capacity for international subsea cable landings while pushing the envelope for the sustainable growth of data centers.

Like many countries at the nexus of this critical infrastructure, Singapore places importance on maintaining the network’s security, performance, and resilience, though its ability to lay and repair cables is hampered by accidental cuts, cabotage restrictions, and the need to find more space for landing stations. That said, Singapore benefits from a century and a half’s worth of industry experience and, in many cases, has set global best practices for limiting accidental cuts from commercial and fishing vessels—particularly important given the country’s busy international trading ports and harbors. Meanwhile, the private sector companies and hyperscalers laying and repairing the cables have to navigate limited landing stations, regional cabotage issues, and permitting challenges related to territorial waters in the region. For example, China’s permitting process for cables going through its marine territorial claims has reshaped cable planning in the region, with several new systems rerouted to avoid the South China Sea.

Singapore maintains a high baseline of security and resilience requirements for all submarine cables in the area. In its waters, all subsea cable providers and operators are required to follow local regulations on submarine cable protection and repair. These include hyperscalers such as Google and Meta; global telecom operators such as the United Kingdom’s Vodafone, Japan’s Nippon Telegraph and Telephone (NTT), Australia’s Telstra, and China’s HMN Tech; and local telecom operators such as Singapore Telecommunications Limited (Singtel) and Keppel. The following country case study provides an overview of Singapore’s subsea cable networks, highlighting key risks and presenting strategic recommendations for expanding and protecting this critical infrastructure.

▲ Map of Subsea Cables Around Singapore

Overview of Subsea Cable Infrastructure

Over the past two decades, Singapore has pursued a deliberate strategy to increase subsea cable capacity and promote geographic route diversity to safeguard against potential service disruptions. It has supported best practices to mitigate risks, including concerns over high-risk equipment suppliers. At the UN General Assembly in 2024, the government also endorsed the New York Joint Statement on the Security and Resilience of Undersea Cables in a Globally Digitalized World (“New York Principles”), which emphasized that “protecting the security, resilience, and integrity of undersea cables is critical to global communications, economic growth, and development.” Thanks to this strategy, Singapore is one of the leading submarine cable hubs in the world, with 28 cables connecting to various landing stations in the country and at least another 13 in the works.

Singapore’s telecommunications market was fully liberalized in April 2000, meaning any domestic or foreign firm can obtain a license to build networks or offer telecom services. Its legal and regulatory frameworks and business environment are designed to attract foreign direct investment (FDI) that has helped boost its digital economy, which accounted for an estimated 17.7 percent of GDP in 2024. Valued at roughly 113 billion SGD ($88 billion), the country’s digital economy is significantly larger than that of its regional peers Malaysia ($60 billion) and Thailand ($36 billion), even though it has a much smaller population. The country continues to lead global benchmarks, ranking first in the world in digital competitiveness, driven by its technological edges (such as internet speed), human capital, and comprehensive digital knowledge base.

Singapore’s subsea cable ecosystem is dominated by long-established regional telecom operators. France’s Alcatel Submarine Networks (ASN), Italy’s Prysmian, the United States’ SubCom, and Japan’s NEC Corporation are the main manufacturers and suppliers of subsea cables. Local and regional companies drive and support the buildout of infrastructure, including Singapore’s Singtel (the country’s largest telecom provider), Keppel, and StarHub, as well as Telkom Indonesia, NTT, the Philippine Long Distance Telephone Company (PLDT), and China Mobile.

In March 2025, Keppel greatly expanded its repair-vessel portfolio when it acquired the UK-based Global Marine Group, bringing its six-ship cable laying and repair fleet under Singaporean management. Although mostly based in Europe, the fleet does include one Singapore-flagged vessel, the Cable Retriever, which is stationed and deployed throughout Southeast Asia. Moreover, an additional two dedicated cable laying and repair ships owned and operated by ASEAN Cableship Pte Ltd. are registered and based in Singapore.

The country’s increasingly robust repair capability presents an important strategic asset for itself and its regional partners in the face of global repair ship shortages.

U.S. tech giants such as Amazon Web Services, Google, Microsoft, and Meta have become active investors in newer cable systems connecting to Singapore, including the Southeast Asian Apricot and the transpacific Echo and Bifrost. The Singapore government’s regulatory backing and geopolitical neutrality helps encourage these and other related investments, including over $5 billion into its data centers and cloud facilities. New cable projects are incorporating faster speeds in data transmission, which will be critical to Singapore’s increased use of AI training models and traditional cloud applications that require immense amounts of data. Given its National AI Strategy and efforts to maintain its edge in global digital trends, the country will certainly continue to focus on a safe and resilient subsea telecom infrastructure.

Governance

The Infocommunications Media Development Authority (IMDA) serves as the lead agency for submarine cable deployment in Singapore. It coordinates interagency approvals and acts as the main point of contact for private operators, even when other government bodies have jurisdiction over specific issues.

To land a new cable, operators are required to

1. apply for or amend a Facilities-Based Operations license from IMDA;

2. consult with the Maritime and Port Authority’s Committee for Marine Projects on the proposed route;

3. seek environmental planning and land-use approvals from the Urban Redevelopment Authority and other relevant government agencies;

4. obtain installation clearance from the Committee for Marine Projects; and

5. apply for wayleave and temporary occupational licenses from government landowners.

Projects are assessed based on financial viability, benefits to the economy and telecom sector, and efficient use of terrestrial and maritime space. Environmental impact reports are required, and applicants are encouraged to include spare fiber to support future network expansion. All systems must land at designated sites allocated on a first-come, first-served basis.

IMDA’s Guidelines on the Management of Submarine Cable Damage Incidents establish standardized protocols for repair and incident reporting. For instance, operators must report damage and damage location to IMDA immediately, coordinate with the Maritime and Port Authority to identify nearby vessels and submit detailed repair plans. The Singapore government has taken steps to make repairs proceed more quickly by shortening permitting timelines. It has also issued guidelines or requirements to help limit and/or prevent accidental damage from vessels or human activity by ensuring cables are buried, that there are “minimum spatial gaps between existing cables and other marine and coastal activities,” regularly updating cable locations on nautical maps, and enacting zones prohibiting anchoring in the Straits of Malacca and Singapore.

Singapore enforces legal protections to deter accidental or intentional damage to its subsea cable infrastructure. The Telecommunications Act criminalizes damage to telecommunications cables or interference with public telecom systems, which could result in jail time or steep fines. Likewise, the Penal Code institutes penalties like prison time and/or fines for disrupting public services. These provisions apply within both Singapore’s territory and territorial waters.

In addition, Singapore is party to the 1982 UN Convention on the Law of the Sea (UNCLOS) in addition to the New York Principles. UNCLOS establishes that damage to subsea cables or other infrastructure within a state’s maritime territory is subject to that state’s criminal jurisdiction, while the New York Principles outline best practices for laying, repairing, and maintaining cables safely and securely. Singapore has not yet acceded to other multilateral treaties governing subsea cable protections, such as the 1884 Convention for the Protection of Submarine Telegraph Cables—which grants countries the right to board merchant vessels suspected of cable tampering, potentially of importance given recent examples of hostile Chinese activities in the South China Sea and Taiwan Strait—and the 1958 Geneva Convention on the High Seas. Together with its own legal frameworks, Singapore could use these international tools to better secure cables against foreign-state tampering and other threats.

International Cooperation

As a member of the Association of Southeast Asian Nations (ASEAN), Singapore has been instrumental in regional initiatives aimed at strengthening submarine cable networks. Since 2013, the organization’s Telecommunications and Information Technology Ministers’ Meetings—now the ASEAN Digital Ministers’ Meetings (ADGMIN)—have recognized the critical “importance of submarine cables to regional and global connectivity” and agreed to “intensify regional cooperation to protect submarine cables from man-made and natural disasters.” Members have taken steps accordingly to expedite cable repairs and reduce regulatory barriers. The 2019 ASEAN Guidelines for Strengthening Resilience and Repair of Submarine Cables sought to further simplify permitting processes across jurisdictions, improving response times for maintenance operations. In February 2024 and January 2025, ADGMIN reiterated these commitments, announcing plans to “build a secure, diverse and resilient submarine cable network” and facilitate regional cooperation in deploying, repairing, and protecting cables. Looking ahead, in an effort to institutionalize coordinated responses, the ASEAN Digital Masterplan 2025 proposes to standardize cable-related practices and to harmonize regulations across the region.

Despite this sense of unity, ASEAN has experienced difficulties in harmonizing policies and engagement, particularly among emerging economic members that lack the governance and financial resources to undertake operations and implement appropriate regulations. Protectionist tendencies further limit cooperation and speedy repairs, with countries like Indonesia, located just off Singapore’s coast, mandating an Indonesian-flagged ship to lay or repair cables within its territorial waters.

Through the New York Principles, Singapore has also committed to conducting regular security risk assessments that facilitate transparency among fellow signatories. In addition, IMDA and Singaporean providers are members of the International Cable Protection Committee (ICPC), and IMDA’s chief executive participates in the International Telecommunication Union’s International Advisory Body for Submarine Cable Resilience, which promotes best practices for installing, protecting, and maintaining submarine cables worldwide.

Recent Developments

The Singapore government continues to invest heavily in the industry and in furthering the country’s role as a regional and international telecommunications hub. In June 2023, the Ministry for Digital Development and Information released its Digital Connectivity Blueprint, which aims to double the number of cable landings within the next 10 years and expand new landing sites, among other priorities. These projects will require an estimated $7.4 billion in investments, predominantly funded by the private sector, and will strengthen Singapore’s role in global data flows, improve network reliability, and diversify cable routes to mitigate potential disruptions.

Thirteen subsea cable projects are either underway or scheduled for completion in the next few years. By the end of 2025, Singapore expects five subsea cable projects to be operational: (1) the Bifrost cable linking Singapore to the United States, Indonesia, and the Philippines, (2) the Echo cable linking Singapore to the United States, (3) the Nongsa-Changi cable linking Indonesia to Singapore, (4) the SEA-H2X cable linking China, Malaysia, Singapore, Thailand, and the Philippines, and (5) the Southeast Asia-Japan Cable 2 (SJC2) which links Southeast Asia to Japan. Nearly all the major domestic and global players in the cable and telecommunications space will engage in one or more of these projects.

Singapore also has several subsea cable projects lined up for 2026, 2027, and 2028, connecting the country to other Southeast Asian countries, the United States (including Guam), the Middle East, and Australia, respectively.

Main Risks to Subsea Cable Infrastructure

The safeguarding of Singapore’s subsea cable systems hinges upon overcoming several significant challenges. As with subsea cables everywhere, accidents remain the most significant threat, and Singaporean waters are particularly brimming with heavy shipping traffic, fishing activities, seismic events, and typhoons. Boundary disputes with Malaysia and Indonesia hinder the management of cables in certain areas; likewise, there is geopolitical friction with China, especially in the South China Sea, as its restrictions on permitting and political leverage prompt costly rerouting of cables to avoid such headaches. Moreover, while the reality of sabotage and intentionally malicious action is unlikely, political anxieties and fears of those threats abound and need to be addressed.

Accidental Cuts

The region is particularly exposed to natural and man-made risks such as seismic activity, typhoons, and heavy maritime traffic, all of which make subsea cables highly vulnerable to damage. Shipping lanes like the Strait of Malacca, which sees around 80,000–90,000 vessels annually, and the South China Sea, which carries roughly one-third of all global shipping each year, are among the busiest in the world. Fishing boats, container ships, and naval vessels frequently pass over or drop anchor in areas where cables are buried. Some cables, especially those laid in the early 2000s, are buried at shallow depths of only a few feet, making them more susceptible to damage from anchor dragging. Even cables buried further down are threatened by deeper excavation and more sophisticated equipment, particularly new, large vessels used for fishing in deep water. Natural disasters such as earthquakes and typhoons are becoming more severe due to climate change, and can further shift the seabed and destabilize continental shelves, resulting in an increased risk of cable damage.

Accidental cuts have been mitigated by Singapore through its Telecommunications Act, which criminalizes damage and enforces no-anchorage zones. IMDA further requires that new cables be buried between 4 and 12 meters (13–39 feet) below the seabed, depending on the context.

Intentional Cuts

Though deliberate sabotage is unlikely, governments in the region will be compelled to find ways to protect cables, especially given the cable cuts in the Baltic Sea and near Taiwan in recent years. As mentioned earlier in this report, Beijing’s regulatory and permitting obstacles and its aggression in the South China Sea certainly raise concerns about the possibilities of intentional sabotage of or tampering with the subsea cable infrastructure running through the region. At the May 2025 International Institute for Strategic Studies Shangri-La Dialogue, Singapore Minister of Defense Chan Chun Sing stated, “We need to work together to defend the entire network. . . . There’s no point trying to defend the integrity and security of a submarine cable by looking at a point. We need both ends to be secure.” The safety of subsea cables was a key topic during the annual forum, and leaders from Europe and the region echoed this call for stronger collaboration to protect global subsea cable infrastructure.

Territorial Waters and Cabotage

Singapore faces several institutional and legal constraints on protecting subsea infrastructure. Because it is so close to Malaysia and Indonesia, Singapore does not have claim over significant maritime territory under UNCLOS, and there are still undelimited maritime boundaries with both neighbors. This restricts the ability of the Singapore government and private sector companies to independently manage and protect cables in certain areas or to lay and repair cables, respectively. Because submarine cables are inherently multijurisdictional, damage often occurs in areas that other states manage.

For companies seeking to land cables in Singapore, Indonesia’s Law No. 17/2008 (“Cabotage Laws”) present an additional challenge. Since they entered into force in 2011, these laws “generally limit domestic sea transportation to [an] Indonesian-flagged vessel.” These rules were marginally relaxed in 2024, allowing some types of vessels to be allowed in Indonesian waters for up to six months if there are no appropriate Indonesian-flagged ones available. Additionally, all vessels in Indonesian waters must obtain a Sea Transportation Company Business Permit and be crewed by Indonesian nationals—though “exemptions may be granted, particularly for Masters and Chief Engineers.” Given Singapore’s proximity to Indonesia, it is nearly impossible to avoid its cabotage laws, which can delay laying or repairing cables. Singapore should therefore strive for partnership with Indonesia, maintaining sufficient cable-repair ships in Indonesia’s waters and developing best practices between cable companies to ensure cuts are repaired as quickly as possible.

In 2024, Malaysia, perhaps learning from the challenges Indonesia has imposed on the industry, reestablished its cabotage exemption for ships under foreign flags to lay and repair cables within Malysia’s maritime zone, waiving the application for a domestic shipping license.

Geopolitics, Permitting, and Surveillance

Geopolitical tensions add another layer of complexity to the security, repair, and laying of subsea cables, particularly in regions such as the South China Sea and Taiwan Strait. While no major cables run through the latter, many connections that ASEAN members rely on do run through the South China Sea, raising concerns that this infrastructure could become collateral damage in a larger geopolitical conflict. The private sector also faces significant permitting and regulatory issues in this region, as China is imposing stricter requirements and taking longer to approve permits for work located in what it sees as its territorial waters, using control over infrastructure projects to hold connectivity hostage to its political demands. Beijing has also “started requesting permits for cable-laying in claimed territorial waters beyond 12 miles, in apparent contravention of international maritime law.”

For example, the SJC2 cable connecting 11 landing stations in Singapore, Cambodia, mainland China, Hong Kong, Japan, Korea, Taiwan, Thailand, and Vietnam was reportedly delayed for over a year because of Beijing’s concerns related to its territorial waters around Hong Kong. According to reporting by the Financial Times, “The authorities cited concerns that the contractor might conduct spying or install extraneous equipment.” This has also resulted in the rerouting of planned subsea cables, including Apricot and Echo, which were originally to pass through the South China Sea but now go through “nonaligned, democratic” Indonesia to avoid the politically sensitive region, gaining increased resilience at increased cost. Unfortunately for cable companies, the South China Sea is the most direct route from Southeast Asia to the United States and Northeast Asia, as well as from Northeast Asia to Africa. According to the cable manufacturers and hyperscalers interviewed for this project, to avoid it adds costs due to longer cable lengths—which are necessary because of the extended route and the deeper waters east of the Philippines—and the need for additional protective measures in shallower waters near Indonesia.

Moreover, the United States has urged cable and telecommunications companies to avoid using Chinese companies to repair or lay new cables due to the (admittedly unlikely) possibility Beijing could intercept and monitor sensitive communications. For example, the New York Principles call for undersea cables to be kept secure from risks of surveillance, sabotage, and stealing data. However, the majority of subject matter experts, industry representatives, and scholars we interviewed felt that tapping cables was not realistic; given the sheer amount of encrypted data passing through the fiberoptic threads, China would have to know how to decrypt and process hundreds if not thousands of terabytes of data per second. When pressed, a few of these interviewees conceded that this may be an issue in the future but noted that there were easier ways to surveil communications and commit corporate or government espionage.

Policy Recommendations

To ensure the security and resilience of subsea cable networks in the country and among its neighbors, Singapore should:

1. Assume regional leadership on regulatory best practices.

   Given the transboundary nature of cable infrastructure, regional cooperation is crucial. Within Southeast Asia, Singapore is well-positioned to lead efforts to enhance submarine cable security, for example by leveraging its role as a digital hub to promote structured information sharing through its Information Fusion Center (IFC), a maritime security facility. As suggested by the S. Rajaratnam School of International Studies (RIS), the IFC should serve as the regional coordinator for cable-related incidents, enabling real-time data exchange between governments and the cable industry. Singapore could propose a standardized regional protocol wherein cable operators report faults to national authorities, who in turn notify their representatives at the IFC. The IFC would then analyze maritime activity near the fault location using satellite imagery and Automatic Identification System data, which surveils vessel traffic, to detect suspicious activities. If intentional tampering is suspected, the center would coordinate an appropriate response with regional navies.

   At the ASEAN level, Singapore should advocate for members’ active participation in the ICPC to stay informed on global industry developments and best practices, ensuring that regional policies align with international standards. ASEAN member states could also create a shared database on submarine cables in Southeast Asia to enhance transparency and streamline cross-border coordination. This database should include detailed information on cable routes, ownership structures, national regulatory frameworks, and the location of cable ship bases.

   Additionally, Singapore should share its best practices for limiting accidental cable cuts in its waters with other ASEAN states. Since so many cables traverse its waters and cabotage laws slow the ability to repair them, enforcing better mechanisms to prevent cuts and enhance accountability would be in Singapore’s and the region’s best interests.

2. Engage on regional cabotage issues and push for flexibility.

   As Singapore has limited maritime entitlements and undelimited boundaries with Indonesia and Malaysia, the cables running out of Singapore’s landing stations almost immediately exit its territorial waters. Indonesia’s strict cabotage laws slow the process of laying and repairing cables, impacting digital connectivity in the region and beyond. Singapore and Malaysia should work with Indonesia to ease these requirements, citing the potential benefits and drawing upon the changes Malaysia has made to its own laws. This cooperation could extend to identifying new landing stations in Indonesia to expand connectivity and redundancy in the region, allowing for more cables to be added to the network.

3. Rethink national strategy.

   Singapore has limited terrestrial and maritime space, so its government agencies will have to work with the private sector to find creative solutions to expanding its cable infrastructure. Since it cannot build many new landing stations, for example, it should consider policies to make its existing ones more efficient and resilient. It should formally designate submarine cables and their associated landing stations as critical information infrastructure (CII) under the Cybersecurity Act of 2018 to offer clarity and legal grounding for more decisive protective action. Submarine cable landing stations and related infrastructure are already subject to certain security and resilience requirements, including reporting cable incidents to IMDA promptly. CII designation would mandate technical hardening of network management systems, vulnerability reporting, and regular audits as well, thereby directly mitigating risks posed by cyberattacks.

   In terms of international law, incorporating Article 113 of UNCLOS into its domestic legislation would extend Singapore’s authority to penalize damage caused by its citizens or registered vessels, even when the incident occurs in another country’s territorial waters or on the high seas. Singapore could also explore applying the “effects doctrine,” a principle in international law that permits states to assert jurisdiction over extraterritorial acts if those acts produce substantial effects within their territory. This would allow Singapore to prosecute cable disruptions originating abroad if they significantly impair Singapore’s own telecommunications networks.

4. Enhance collaboration with the private sector.

   Given that most submarine cables are privately owned, strong public-private collaboration is essential to safeguard them. The government should enhance proactive risk management by establishing a centralized threat-monitoring system to log early warning signs, such as repeated faults or atypical vessel movements near cable routes, that may not meet formal incident thresholds but still warrant scrutiny. While IMDA already requires cable operators to report all damage in Singapore territory promptly, cable companies should be required to report all suspicious activity and response measures in real time. IMDA, as the central coordinating agency, would then disseminate this information to relevant stakeholders. The agency could also conduct regular tabletop exercises simulating cable disruptions or cyberattacks to test the resilience of key actors such as cable operators and cybersecurity agencies. These drills would strengthen preparedness and expose operational blind spots.

5. Pursue global engagement and cooperation.

   Globally, Singapore should continue to leverage its providers’ existing membership in the ICPC to advocate for stronger public-private information sharing, rapid repair coordination, and international mechanisms to respond to sabotage or state-sponsored threats. As geopolitical tensions in areas such as the South China Sea influence cable routing decisions, it will be vital for Singapore to coordinate with U.S. agencies and hyperscalers on secure cable routes, share infrastructure protection protocols, and follow cybersecurity best practices. The United States and Singapore can also collaborate on research and development related to detecting cable faults, conducting repairs, and tailoring cyber defenses for underwater infrastructure.

Conclusion

Singapore’s position as a global subsea cable hub is integral to both its economic stability and the security of global digital communications. The rising frequency of cable damage incidents underscores the urgent need for swift, coordinated responses to safeguard this critical network. Although the country has made significant strides in expanding its infrastructure and enhancing resilience, there are still opportunities to further strengthen these defenses. Doing so will require a comprehensive approach, including imposing tougher criminal penalties, recognizing cables as critical infrastructure, and enhancing coordination between government agencies and private partners. Continued investment in technology, diversification of cable routes, and bolstering cybersecurity will cement Singapore’s role as a digital hub. Fostering stronger regional and international cooperation is also vital for mitigating risks from geopolitical tensions and securing global connectivity.

Erin Murphy is deputy director of Chair on India and Emerging Asia Economics and senior fellow of Emerging Asia Economics at the Center for Strategic and International Studies (CSIS) in Washington, D.C.

Thomas Bryja is a program manager and research associate for the Project on Prosperity and Development at CSIS.