Finland Detains Vessel With Russian Ties Over Baltic Sea Cable Sabotage

In a decisive move underscoring the escalating tensions in the Baltic Sea, Finnish authorities have detained the oil tanker Eagle S, a vessel linked to Russia’s so-called “shadow fleet.” The ship is suspected of causing significant damage to critical undersea infrastructure, including the EstLink 2 power cable and multiple internet lines connecting Finland, Estonia, and Germany.

The Incident

On December 25, 2024, the EstLink 2 submarine power cable experienced an unplanned failure, reducing the electricity transmission capacity between Finland and Estonia from 1,016 MW to 358 MW. At the time of the outage, electricity was flowing from Finland to Estonia at a rate of 658 MW. The Finnish transmission system operator Fingrid anticipates that repairs will extend into August 2025, raising concerns about energy security during the harsh winter months.

Concurrently, disruptions were reported in four telecommunications cables originating from Finland. Two of these cables, owned by Finnish operator Elisa, were completely severed, while a third link between Finland and Estonia, owned by China’s Citic, sustained damage. Additionally, a fourth internet cable running between Finland and Germany, belonging to the Finnish group Cinia, was believed to have been severed.

About the EstLink 2

The EstLink 2 is a high-voltage direct current (HVDC) submarine power cable that connects Finland and Estonia across the Gulf of Finland. This critical infrastructure has a transmission capacity of 650 MW, which, when combined with the existing EstLink 1, increases the total capacity between the two countries to 1,000 MW. The cable system consists of several components, including a 14 km overhead line in Finland, a 145 km submarine cable beneath the Gulf of Finland, and a 12 km underground cable in Estonia, giving it a total length of about 170-171 km.

EstLink 2 operates at a voltage of 450 kV DC and was commissioned in 2014 at a total cost of €320 million, with €100 million funded by an EU subsidy. The project was developed through a partnership between Finland’s Fingrid and Estonia’s Elering. Its main purpose is to enhance power system security and integrate electricity markets within the Baltic Sea region. The cable supports bidirectional power flow between the two countries, improving energy security and market efficiency for the region.

The Vessel: Eagle S

The Eagle S, a Cook Islands-registered oil tanker, was intercepted by the Finnish Coast Guard in the Baltic Sea. The vessel is believed to be part of Russia’s “shadow fleet,” a term used to describe aging tankers that operate clandestinely to evade international sanctions, particularly those imposed on Russian oil exports.

Finnish customs officials have seized the ship’s cargo, and the National Bureau of Investigation is probing the incident as an act of “grave sabotage.”

Investigators suspect that the damage was caused by the ship’s anchor, which may have dragged along the seabed, disrupting the cables. Notably, the Eagle S was observed crossing the path of the EstLink2 electricity cable at the exact time the outage occurred, further implicating the vessel in the incident.

The Eagle S oil tanker was taken into custody through a well-coordinated operation by Finnish authorities following the damage to critical power cables. Acting swiftly, Finnish officials managed to get the tanker to stop in Finnish territorial waters, giving them the legal authority to board the vessel. The boarding, described as a “tactical operation” by Finnish police, was a joint effort involving the Finnish police, Border Guard, Defense Forces, and Coast Guard.

The operation began in the early hours of December 26, 2024, with Defense Forces helicopters providing access to the tanker. The boarding took place at approximately 12:28 AM local time. 

After the boarding, the Eagle S was seized and is now held in Finnish waters near Porkkala. Finnish authorities have also established a no-fly zone over the area where the vessel is being held to secure the investigation site and ensure safety.

About Russia’s Shadow Fleet

Russia operates a shadow fleet of ships using various strategies to sidestep international sanctions and continue exporting oil and other commodities. This fleet, developed with an estimated $10 billion investment, mainly consists of aging, poorly maintained vessels with unclear ownership and limited or no insurance coverage. Many of these ships are linked to Russian companies like Rosneft, which use overseas entities with obscure ownership structures to market and sell oil.

The fleet employs several tactics to avoid detection and regulation. Ships often use “flags of convenience,” registering under permissive countries like Gabon, Eswatini, Comoro Islands, and Guinea-Bissau. To evade tracking, vessels switch off their Automatic Identification System (AIS) transponders, effectively “going dark,” or use “spoofing” to transmit false location data. They also engage in ship-to-ship transfers to hide the origin of their cargo and manipulate documentation, sometimes presenting fake customs compliance papers that misrepresent the actual prices of exported goods.

By mid-2024, this shadow fleet was responsible for transporting over 70% of Russia’s oil and oil product exports, including 89% of crude oil and 38% of oil products. Estimates place the fleet size at around 435 to 591 vessels, depending on the source. Russia has even expanded its shadow fleet operations into liquefied natural gas (LNG), with approximately 50 vessels, including nine confirmed shadow ships.

These operations come with significant risks. The shadow fleet’s lack of adherence to international regulations, coupled with poor maintenance, raises concerns about environmental harm, maritime safety, and global security. Despite these challenges, the shadow fleet remains a critical component of Russia’s strategy to maintain its exports under the pressure of international sanctions.

International Reactions

The incident involving the Eagle S tanker and the damaged EstLink 2 power cable has triggered strong reactions from international authorities and organizations. The European Union, through foreign policy chief Kaja Kallas, described the event as “the latest in a series of suspected assaults on critical infrastructure.” Kallas commended Finnish authorities for their swift response and highlighted the dangers posed by Russia’s shadow fleet. These vessels threaten security and the environment, as well as helping to finance Russia’s military. In response, the EU is considering additional sanctions and measures to address the shadow fleet’s activities.

NATO has also been involved, with Estonia, a member of the alliance, taking steps to safeguard its maritime infrastructure. Estonia deployed its patrol ship Raju to monitor the waters around the EstLink 1 cable and has called on NATO allies to assist in protecting critical undersea assets. This reflects growing concern among NATO countries about the security of undersea infrastructure in the Baltic Sea.

The incident has sparked increased cooperation among Baltic and Nordic nations. Finnish authorities are working closely with Estonian counterparts to investigate the damage, while Sweden and Poland are also evaluating the broader impact on undersea infrastructure in the region. This collaborative effort underscores the importance of regional partnerships in addressing such threats.

Internationally, the seizure of the Eagle S has drawn attention to the broader issue of maritime security in the Baltic Sea. European officials have linked this and similar incidents to Russia’s invasion of Ukraine, suggesting a pattern of sabotage targeting critical infrastructure. Finnish Prime Minister Petteri Orpo emphasized the urgency of developing strategies to counter the shadow fleet operating in the Baltic.

Although direct accusations against Russia remain limited, the incident has heightened global awareness of the vulnerabilities facing undersea infrastructure and the risks posed by vessels linked to Russia’s shadow fleet.

Broader Context

The incident involving the Eagle S tanker and the damaged EstLink2 power cable has triggered strong reactions from international authorities and organizations. The European Union, through foreign policy chief Kaja Kallas, described the event as “the latest in a series of suspected assaults on critical infrastructure.” Kallas commended Finnish authorities for their swift response and highlighted the dangers posed by Russia’s shadow fleet. These vessels not only threaten security and the environment but also help finance Russia’s military. In response, the EU is considering additional sanctions and measures to address the shadow fleet’s activities.

NATO has also been involved, with Estonia, a member of the alliance, taking steps to safeguard its maritime infrastructure. Estonia deployed its patrol ship Raju to monitor the waters around the Estlink 1 cable and has called on NATO allies to assist in protecting critical undersea assets. This reflects growing concern among NATO countries about the security of undersea infrastructure in the Baltic Sea.

The incident has sparked increased cooperation among Baltic and Nordic nations. Finnish authorities are working closely with Estonian counterparts to investigate the damage, while Sweden and Poland are also evaluating the broader impact on undersea infrastructure in the region. This collaborative effort underscores the importance of regional partnerships in addressing such threats.

Internationally, the seizure of the Eagle S has drawn attention to the broader issue of maritime security in the Baltic Sea. European officials have linked this and similar incidents to Russia’s invasion of Ukraine, suggesting a pattern of sabotage targeting critical infrastructure. Finnish Prime Minister Petteri Orpo emphasized the urgency of developing strategies to counter the shadow fleet operating in the Baltic. Although direct accusations against Russia remain limited, the incident has heightened global awareness of the vulnerabilities facing undersea infrastructure and the risks posed by vessels linked to Russia’s shadow fleet.

Implications and Future Actions

The detention of the Eagle S underscores the urgent need for enhanced surveillance and protection of undersea infrastructure in the Baltic region. The European Union and NATO have both indicated their commitment to supporting member states in safeguarding these critical assets. Additionally, there are calls for increased sanctions against Russia’s shadow fleet to deter further clandestine activities.

As investigations continue, the incident reminds us of the geopolitical tensions simmering beneath the surface of the Baltic Sea. The deliberate targeting of infrastructure disrupts essential services and poses significant risks to regional stability. It is imperative for nations bordering the Baltic to collaborate closely, share intelligence, and bolster their defensive measures to counteract these emerging threats.

Summing Up

The apprehension of the Eagle S by Finnish authorities marks a pivotal moment in the ongoing efforts to protect the Baltic Sea’s undersea infrastructure. The incident highlights the complex interplay between maritime security, energy supply, and geopolitical strategy in a region of critical importance to Europe’s stability and security.