By Olha Chepil | 2026-04-08

The Baltic seabed carries 94% of the world's communications and a growing share of Europe's electrical power. Now Finland and its Baltic neighbors are building a system to protect it.

Together with the European Commission, they are establishing a maritime surveillance center to monitor undersea cables, power connections and gas pipelines and to catch threats before damage is done.

The Finnish Border Guard announced the program in January. Its head of security, Mikko Hirvi, told Reuters the time for passive observation is over.

"Our forces are developing, and we need broader preventive measures, even before any harm has occurred," he said.

A system built on three pillars

The Baltic Sea floor holds one of the densest concentrations of undersea infrastructure in the world. Hundreds of cables crossing the seabed carry internet services, banking transactions, corporate data and electrical power between countries. They were laid by different operators with no unified protection system, leaving critical infrastructure essentially open.

"There are practically no special protection measures deployed. In theory, it's just, lie there on the seabed and don't bother anyone," said Mykhailo Gonchar, a Ukrainian analyst and president of the Centre for Global Studies Strategy XXI, told Kontur.

Geography compounds the problem. The Baltic Sea is shallow -- an average depth of 59 meters (about 194 feet) and a maximum of 400 meters (0.2 miles) -- which makes cables easier to lay, but also easier to access and sabotage. Their routes aren't classified either.

"If you do a Google search for 'submarine cables,' you'll see a diagram of these cables that shows where they run. It's not a secret," said Andriy Ryzhenko, a captain of the first rank of the Ukrainian navy reserve and a strategic expert at Sonata, a consulting company.

Analysts say the new surveillance system will rely on three pillars: seabed sensors that record disturbances to the ocean floor, artificial intelligence (AI) algorithms that track suspicious vessel behavior, and an intelligence coordination center linked to the EU and NATO. The system will also incorporate underwater acoustic monitoring and aerial surveillance drones.

The goal is to catch anomalies in real time.

"This allows you to document irregularities — for example, if a vessel suddenly stops or uses an anchor in the vicinity of where cables are laid. You need to find out why it's happening," Gonchar said.

Previously, identifying a responsible vessel could take weeks. Some ships traveled with their transponders switched off. Investigators were left analyzing every vessel in the region.

"Time was spent on this because they were analyzing all the vessels in the region," Gonchar said. "Some vessels travel with their transponders off and aren't identified."

The new approach prioritizes surveillance and coordination over military presence.

"They see the answer less in stepping up the military presence and more in surveillance and coordination," Gonchar said. "This all entails the development of surveillance, coordination and information sharing systems. This is a crucial response to threats like these."

From accidents to sabotage

The shift from ambiguity to attribution came in stages. A series of incidents in the Baltic, initially treated as accidents, grew harder to dismiss as they recurred.

One early incident illustrated the detection problem. In October 2023, the Balticconnector gas pipeline and a telecom cable between Finland and Estonia were damaged when a Chinese cargo ship dragged a six-ton anchor roughly 185 kilometers (115 miles) along the seabed. Gonchar was skeptical the crew didn't know.

"The vessel dragged the anchor around 185 kilometers along the seabed. How could the captain not notice that? It would have caused a huge vibration and loss of speed that's impossible to shrug off," he said.

The turning point came when Finnish special forces detained the dry cargo vessel Fitburg, traveling from Saint Petersburg to Haifa, after a telecom cable between Finland and Estonia was severed. Finnish intelligence concluded it was premeditated sabotage by Russia. NATO responded by launching the Baltic Sentry mission, deploying patrols to follow suspicious vessels in the Gulf of Finland.

Russia, analysts say, has both the technical capability and specialized units for these operations -- from reconnaissance vessels to submersibles.

"They have the units and vessels that can work with these kinds of assets, including inflicting damage, wiretapping and planting explosives," Ryzhenko said. "The Russians have been doing this for a rather long time. They have specialized units to strike a blow against these cables."

What happens when a cable breaks

For ordinary users, a damaged cable may look like slow internet or a disrupted mobile connection. Behind that, banking transactions stall and digital services degrade. In the Baltic region, the stakes extend further -- undersea lines also carry high-voltage electrical power between countries.

"When a cable is damaged, users may notice that their connection is disrupted even though operators usually switch traffic over to backup lines," Gonchar said. Damage can affect communication, energy supply and the economy simultaneously.

Backup routes have so far prevented single incidents from causing catastrophic failures. The real danger, analysts say, is a coordinated mass attack on multiple cables at once.

"The danger is in a potential mass attack on a large number of cables, including strategically important ones, in places where NATO cables run too," Gonchar said.

Every disruption on the seabed, analysts warn, surfaces quickly in daily life -- in slow internet speeds, interrupted bank transfers and gaps in electrical supply. The new surveillance center is designed to make sure the next incident is caught before it becomes a crisis.