Russian fishing boats loitered above critical communications cables more than 500 times in four and a half years, according to analysis by The Telegraph, and a NATO representative says some of them never see a fish.
The analysis used satellite data from Global Fishing Watch, which tracks vessels over open ocean. The Telegraph cross-referenced those tracks against nautical charts that mark cable routes. Charts show roughly where cables lie so ships can avoid them. Anyone planning work on a cable needs far more precise positioning than that.
The paper gave three examples. One ship followed nine separate Atlantic cables, including Atlantic Crossing 1 and the decommissioned TAT-14. Another lingered near Hibernia Express, then tracked the Shefa-2 cable between Shetland and the Faroe Islands. A third partly followed Amitie and Grace Hopper, which link the UK, France and Spain to the U.S. Some ships slowed to two or three knots.
A senior naval officer said vessels of this size could carry an uncrewed surface vehicle or a remotely operated vehicle (ROV), a tethered robot submarine. "If you put a sonar-equipped ROV 100 meters above a feature of interest, you can map it with millimeter precision," the officer said.
The evidence is circumstantial, and that is the point of the tactic. Trawlers also move slowly, and a track on a map shows where a boat went, not what it did. That ambiguity is why this counts as gray-zone activity: deniable, and hard to pin on the Kremlin.
The stakes are large. An estimated $87 billion of economic activity passes through undersea cables. Past cases include two cables cut in the Baltic in 2024, one linking Finland and Germany and the other Estonia, and a Chinese freighter Taiwan detained over a damaged cable.
Mapping is not sabotage, and the law treats it that way. Most cable length sits in international waters, where vessels may pass freely. Navies can shadow suspicious ships, but that behavior is generally not grounds for boarding, detention or seizure. So 500 logged incidents leave defenders with plenty of evidence of interest and very little legal room to act on it.