The Eagle S and the Threat to Underwater Infrastructure

Media outlets reported that Finnish authorities have seized a ship in the Baltic Sea on suspicion it caused the outage of an undersea power cable connecting Finland and Estonia. 

This ship, known as the Eagle S, docked in Ust Luga, Russia on December 23, 2024. It disabled its AIS signal for ten hours, reappearing two days later on December 25. That evening, the vessel sailed slowly above the undersea Estlink 2 power cable in the Gulf of Finland, coinciding with a sudden cable outage. 

Windward’s AI models classified the Eagle S as a moderate sanctions compliance and security risk. Key factors contributing to this assessment include:

• Lack of P&I insurance: a red flag in the maritime industry
• Flagged by the gray fleet model: the vessel was carrying 35,000 tonnes of Russian petrol when it was apprehended
• Flag of convenience: registered under the Cook Islands and classed by the Indian Class Society
• Spy ship capabilities: the Eagle S had numerous transmitting and receiving devices, transforming it into a potential surveillance asset for Russia

The Importance of Early Intelligence

This is the third undersea cable damaged in the Baltic region in the past few months. These incidents highlight the growing vulnerability of underwater critical infrastructure – a pressing issue tied closely to national security, resilience, and geopolitics.

In November, two undersea internet cables were suddenly disrupted, with one of them being the C-LION1, the only direct connection of its kind between Finland and Central Europe. Consequent reports strengthened the suspicion that this was an act of deliberate sabotage.

Windward Early Detection flagged suspicious activities in the Baltic Sea, weeks before the C-Lion disruption. Such insights, when acted on promptly, can avert potential crises by alerting law enforcement agencies ahead of time.

The Blurred Line Between Military and Commercial Activity

According to Windward insights, over the past six months, nearly 26,000 area visits have been made by approximately 1,400 Shadow Fleet vessels or Russian-related vessels. 

The Eagle S exemplifies the growing overlap between commercial and paramilitary operations. With surveillance equipment aboard a merchant vessel, the question arises: are these ships truly commercial or covertly government-operated? This ambiguity is further complicated by UNCLOS, which allows freedom of passage for merchant vessels but excludes intelligence gathering under Article 19, 2. (c). Proving breaches of innocent passage could lead to significant legal and operational consequences.

Risks Posed by the Shadow Fleet

The Eagle S is just one of approximately 1,300 vessels in Russia’s “shadow fleet.” These ships, often evading sanctions, present a dual threat: sanctions compliance and security risks. If evidence of espionage emerges, it could trigger stricter monitoring and sanctions from port operators, insurance providers, and international regulators.

While governments must bolster independent capabilities to procure and act on maritime intelligence, energy companies can’t rely solely on state measures. The entities laying critical infrastructure like undersea cables must assume accountability for securing their assets against threats. Collaborative approaches involving the public and private sectors are essential to mitigate vulnerabilities.

What Comes Next?

The detention of the Eagle S could mark a turning point in maritime security. If Finnish authorities establish proof of espionage or sabotage, it may lead to:

• Stricter legal frameworks for maritime operations in sensitive regions
• Heightened scrutiny of vessels linked to the shadow fleet
• Increased pressure on commercial actors to adopt proactive security measures

In an interconnected world where global trade and energy rely on secure underwater infrastructure, safeguarding these critical assets is essential.

Windward’s Early Detection capabilities enable organizations to flag anomalies, identify emerging trends, and prioritize deeper investigations. Our technology and domain expertise empower users to monitor underwater infrastructure in real-time and conduct detailed post-incident investigations. From identifying suspicious activities to enhancing the physical security of undersea cables, Windward helps mitigate risks before they escalate into crises.

The protection of underwater infrastructure remains alarmingly inadequate in many regions and damages can occur without immediate detection. This often leaves critical systems vulnerable to disruption. Addressing this challenge requires a collaborative effort from governments, security organizations, and industry leaders to strengthen monitoring and response strategies. With proactive intelligence solutions, the maritime industry can move from reactive measures to predictive safeguarding – ensuring the resilience of vital underwater infrastructure and the global systems it supports.

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