What NATO patrols are watching in the Baltic Sea after undersea cables were severed

CBC

14-02-2025

On the bridge of the Estonian warship Sakala, a crew member out on patrol moves a camera, zooming in on a Panama-flagged oil tanker 300 metres away in the Gulf of Finland.
The tanker, which left a Russian port bound for Egypt, is considered by maritime experts to be a member of Moscow's shadow fleet — often old tankers with opaque ownership that try to work around international sanctions.
At a time when the eight NATO nations bordering the Baltic Sea are on high alert after a string of undersea power and internet cables were suspiciously severed, Russia's shadow fleet is getting extra attention.
"We are here to guard our waters," said Lt. Cmdr. Meelis Kants in an interview with CBC News on Wednesday.
"If ships are really doing something suspicious, we will stop them."
More patrols
The Sakala, which is a minehunter, is one of three Estonian ships that have been sent to patrol a stretch of the Baltic Sea near the mouth of the Gulf of Finland and near the site of two underwater power cables that connect Estonia to Finland.
One was severed on Dec. 25 of last year, along with four internet cables.
At the time, it was the third incident in five weeks where undersea cables were damaged — and suspicion centred around ships connected to Russia.
Since then, Estonia and Finland have boosted their patrols, along with NATO, which has sent frigates, aircraft and naval drones to the area as part of the operation Baltic Sentry.
While investigations into the damaged cables are still ongoing, and there appears to be divided opinion on whether the incidents were accidental or sabotage, NATO countries are concerned enough that they have stepped up monitoring in order to protect the critical infrastructure.
In Estonia's case, the navy is patrolling by looking out for suspicious activity, such as anomalies with anchors and where they are supposed to be positioned. Other red flags include if a ship quickly changes speed or is ignoring radio communication.
No issues since patrols began
Over the past two months, the crew on the Sakala said they looked into 50 potentially suspicious activities. But upon closer inspection, there have been no issues.
The day before the crew took media including CBC News on patrol, they said they had started watching a vessel after they noticed something wrapped around its anchor. It turned out to be a hose.
The Sakala communicated with the ship and shadowed it until the hose was removed.
There wasn't an issue in that case, nor have they encountered any threatening actions over the past two months.
"We don't see anything suspicious happening, so that's already good," Kants said.
"But if we weren't here, I don't know what would happen."
The Baltic Sea stretches from St. Petersburg, Russia, to Denmark, and is one of the world's busiest shipping lanes.
Every week, 500-600 ships transit the Gulf of Finland. Their positions are tracked, but it's what is happening below the surface that is murkier, and why NATO countries are trying to deter any threats against the subsea cables on the bottom of the sea floor.
Crucial cables
The cables span the world's oceans and seas, together stretching 1.5 million kilometres around the globe.
The fibre optic communication cables are referred to as the backbone of the internet, carrying 95 per cent of the world's data.
While between 150-200 cables are damaged every year by anchors, commercial fishing and even environmental factors like submarine landslides, the fact that there were three incidents in the same area over a relatively short time period has raised suspicions.
"Is it intentional or is it an accident? It's difficult to answer," said Capt. Johan-Elias Seljamaa, deputy commander of Estonia's navy.
"But the fact is that prior to those [recent incidents], there was no damage in such magnitude and in those areas."
Before the cables were severed on Dec. 25, there were two separate incidents just over a month earlier.
A 218-kilometre internet cable between Lithuania and Sweden's Gotland island was damaged on Nov. 17. The following day, a 1,200-kilometre cable connecting the Finnish capital of Helsinki to the German port of Rostock was severed.
At the time, suspicion centred around a Chinese bulk carrier, the Yi Peng 3, which was carrying Russian fertilizer.
While China initially allowed investigators from Germany, Sweden, Finland and Denmark to board the ship, Swedish officials later said China didn't heed the government's request for a prosecutor to be able to conduct a preliminary investigation on board.
The ship eventually departed for Egypt.
Anchor dragged for 100 km
After the next series of cables were severed on Dec. 25, Finnish investigators seized the Eagle S, an oil tanker suspected of being part of Russia's shadow fleet.
Finnish police said that an anchor, which was later recovered, was suspected of being dragged around 100 kilometres along the seabed.
Seljamaa says since Russia's full-scale invasion of Ukraine in 2022 and the ensuing sanctions, the ship traffic they are seeing in the Gulf of Finland has changed.
He says there are now older vessels with more inexperienced crews, but even with that, he says he doesn't know how an anchor could be accidentally dragged for 100 kilometres.
"I don't believe that you couldn't feel it or detect it," he said.
Russia has denied sabotaging the cables, calling it "ridiculous" against the backdrop of the Nord Stream explosions in 2022, which damaged the gas pipelines that ran between Russia and Germany under the Baltic Sea.
While an official investigation into the Nord Stream blast has never been released publicly, several media outlets, including the Wall Street Journal, have reported that a group of Ukrainian nationals were behind the explosion.
In the wake of that incident, Dmitry Medvedev, the deputy chair of the Security Council of the Russian Federation, warned"the complicity of Western countries" meant Russia had "no constraints" and could destroy the west's undersea communication cables.
Doubts about the damage being deliberate
After the cables were damaged late last year, the European Union said it was the latest in a series of attacks on critical infrastructure.
But two media reports have recently raised doubts that the acts were deliberate.
WATCH | This Estonian warship is patrolling the Baltic Sea:
On board a ship watching for suspected Russian sabotage
4 minutes ago
Duration 2:46
We're on board one of the NATO patrol ships protecting important underwater cables in the Baltic Sea. CBC News's visual investigations team mapped the sequence of recent damage to cables in the area that some are saying is Russian 'shadow fleet' sabotage.
Reports by the Washington Post and The Associated Press both cited unnamed officials who said the evidence pointed to an accident and not sabotage.
At the end of January, a cable between Latvia and Sweden was damaged and a Bulgarian vessel was under investigation, but Swedish officials determined it was not sabotage.
Last week. Russia said that it discovered one of its cables in the Baltic Sea had been damaged by what officials called an "external impact."
On board Estonia's Sakala, those in charge are careful with their words. They don't directly accuse Russia of sabotaging the cables, but they make it clear that they view the country as a threat.
They say if a ship is behaving suspiciously and won't respond to radio calls, then Seljamaa says they will respond, including by force.
But Michael Plunkett, a U.K.-based senior naval analyst for Janes, an open-source global intelligence company, says recognizing suspicious activity may be one thing, but responding to a ship in international waters is another.
"Are they able to stop it? Are they able to board it? If it's in international waters, then they are on some fairly shaky legal ground," said Plunkett in an interview with CBC News by Zoom.
But he says the enhanced patrols alone will likely have an impact.
"It sends the message that NATO is aware of the potential threat and it is going to try to deter the more brazen attempts at sabotage."