NATO may turn to using a fleet of sea drones to protect vulnerable Internet cables in the Baltic Sea

In the wake of two severed Internet cables in the Baltic Sea, NATO is reportedly working to deploy a new type of underwater surveillance to protect them. 

NATO Admiral Pierre Vandier told Defence News the alliance is working on a permanent way to have eyes above and below the water for any potential cable sabotage. 

The network of unmanned surface vehicles (USVs) or drone ships would work like street-lights to find if and when any underwater crime is occuring, both on the surface of the water and below, Vandier told the news site. 

The new strategy comes just weeks after two Baltic Sea cables - one connecting Lithuania to Sweden and another from Finland to Germany - were disrupted in an apparent sabotage operation. 

Investigations by the Swedish and Finnish governments are still underway. 

Euronews Next takes a look at what drone ships and sea drones are, what they do and what the implications are for NATO’s new autonomous fleet. 

What are drone ships and sea drones?

Sea drones are small, unmanned vessels that work either on the surface or below the water. 

Andrej Zvaigzne, senior researcher at the Institute of Applied Computer Systems at Riga Technical University, told Euronews Next there are different types of underwater drones: those that focus on surveillance, some that focus on identifying threats and others that can be programmed to destroy enemy movements. 

The ideal system for sea surveillance looks and feels like air traffic control, Zvaigzne said, where radars control how and when aircraft monitor and potentially hit their targets. 

“You want to understand what is going on, which targets [are] moving from left to right… so you have control over all situations,” he said. 

Individual countries and bodies like NATO will have to ask what they want out of these drones, for instance, whether the priority is 24/7 surveillance or drones that will be able to retaliate if an enemy ship is conducting suspicious business in the area, Zvaigzne said. 

There are already some companies that operate sea drones in the Baltic Sea, but Zvaigzne said it’s hard to know how many are already operational. 

'You can never get it 100 per cent'

In general, Zvaigzne said it’s hard to communicate with the underwater drones if they are travelling for a long distance. 

"There’s no time control on the drone so it can be gone for half an hour or two hours," Zvaigzne said. 

The Baltic Sea also has "poor visibility" due to different "water layers," according to Zvaigzne, making it hard to see what is going on, but some drones get around this by using sonars. 

Even with a robust system in place, it still might be difficult for NATO or Baltic States to differentiate between an accidental hit to the underwater cables and intentional sabotage. 

"It's like with any crime, you can never get it 100 per cent… but of course it reduces the level of crime," he said. 

'The next question is how to react'

So far, the coordinated response under the sea to any subsea sabotage is limited, according to Olevs Nikers, President of the Baltic Security Foundation. 

There are some periodical controls done by underwater drones in the Baltic Sea, but no coordination between individual states, NATO and telecommunications operators on where the drones are needed and when, Zvaigzne added. 

All Baltic Sea countries besides Russia are now NATO members because of Sweden and Finland’s recent membership, prompting the Baltic Sea to be rechristened as "NATO Lake" in some quarters.

What needs to happen, according to Zvaigzne and Nikers, is for all the Baltic States to pass legislation to make it easier to surveil the underwater cables and to decide the legal repercussions if sabotage is detected. 

"Let’s say crime is really happening… the next question is how to react," Nikers said. "What would be those algorithms for a coherent and coordinated reaction?"

Euronews Next reached out to NATO to confirm the sea drone reports but didn’t receive an immediate reply. 

NATO had previously told us in a statement that it had discussed information-sharing and ways to deter and defend against undersea infrastructure threats with an underwater critical infrastructure working group.