The long watch: From Svalbard to the Dover Strait

Take a chart of the North-East Atlantic and trace a line with your finger.

Start at Svalbard, high above the Arctic Circle. Come south past the North Cape and down the Norwegian coast. Cross the Norwegian Sea, through the gap between Greenland, Iceland and the UK. Past Shetland. Past Aberdeen. Down the North Sea, and into the Dover Strait, the busiest shipping lane on Earth, narrow enough to see France from the beach.

That is not six theatres. It is one waterway. And what happens at the top of it arrives at the bottom of it, usually within a fortnight, at 12 knots.

The quiet theatre

Nobody is shooting at merchant ships in the High North. That is precisely why it is dangerous to look away. The threat up there is not kinetic; it is hybrid, patient, and pointed at the things our economies actually run on. Three strands stand out:

• The seabed. This spring, British and Norwegian forces tracked and publicly exposed a month-long Russian operation in the waters north of the UK, with specialist deep-sea units assessed to be mapping subsea fibre-optic cables. When the tracking became visible, the units withdrew. That is the good news. The bad news is the obvious corollary: the deterrent effect of being watched is temporary, and the mapping product goes home with them. Svalbard lost one of its two fibre connections to damage in 2022. Shetland has already lived through days without its cable. Whatever the cause of any single incident, the dependency is not in dispute, and neither, any longer, is the interest being taken in it.
• The hulls. An ageing fleet of sanctioned and shadow-fleet tankers, opaque ownership, recycled names, and insurance that would not survive a claim is transiting the Norwegian coast in growing numbers, and the economics say that traffic will increase through 2026. These ships are not a threat to other vessels. They are a threat to coastlines: a casualty involving uninsured, unmaintained tonnage leaves the coastal state holding the pollution, the salvage bill, and no solvent counterparty behind the hull. The same tonnage, further south, files through the Dover Strait in sight of the shore.
• The data. In the Baltic, satellite-navigation interference originating from Russian territory is now chronic, formally condemned by international aviation bodies, logged by every Nordic state, degrading AIS as well as position-fixing. Read that as a warning for the whole line: the digital picture we habitually treat as ground truth can be bent, and increasingly is.

The line runs south

None of this stays in the High North. The vessels loitering near cable routes off Norway have, on well-documented occasions, done the same in the English Channel and Irish Sea; the UK Defence Secretary has named one of them in public. The shadow fleet that rounds the North Cape passes Shetland’s energy terminals and Aberdeen’s offshore infrastructure, the densest concentration of subsea pipelines, power interconnectors and communications cables in our waters, before it ever reaches Dover.

The UK is not starting from zero here. A cross-government fused maritime picture exists, and the professionals who run it are good at it. The honest question is not ownership; it is depth and persistence. Grey hulls are few and expensive. The coastline is long. Satellite passes are snapshots. A watch, by definition, is continuous. That gap — between episodic patrol and persistent watch — is where hybrid activity lives.

The watch we could stand up now

Here is the part I find genuinely hopeful.

The sensor network we need is already at sea. Every day, thousands of merchant ships, fishing vessels, ferries and offshore support vessels transit exactly the waters we are worried about — each one with a bridge, a view, and a watch being kept. For a century, that view has evaporated the moment the watch changed.

It no longer has to. AI-powered lookout technology, computer vision mounted on working ships, watching continuously, in all weathers, without fatigue, can turn every routine transit into collection: the dark vessel showing no AIS, the tanker loitering where no tanker should, the rendezvous the digital picture never recorded.

Machines are extraordinarily good at the part of watchkeeping humans are worst at: unbroken vigilance. Humans remain irreplaceable at the part machines cannot do: judgment. That division of labour matters.

Technology like this produces indicators, not attribution. The security judgment, what it means, whose it is, what to do, stays with sovereign authorities, where it belongs. But feeding the national picture with persistent, verified observation from the fleet that is already out there narrows the surveillance gap at a speed and cost no warship-building programme can match this decade. Ships as sensors. Ports as checkpoints. Data treated with professional scepticism. And people, crews, pilots, agents, surveyors, as the human layer that reads what sensors cannot.

Andrew Cowderoy is a UK-based maritime intelligence and shipping-risk specialist. You can read more of his work on LinkedIn.