Fourteen States Issued a Joint Warning
In January 2026, thirteen European nations and Iceland issued a joint statement warning that GNSS interference is degrading the safety of international shipping in European waters. Governments do not usually coordinate a statement of that kind about a technical nuisance.
The scale behind it explains why. Since the start of 2025, the number of GPS spoofing installations attributed to the Russian Federation has risen from three to thirty-six. Interference in the Baltic is no longer episodic; across large parts of the region almost all GNSS signals are routinely jammed, and the European Union has announced sanctions in response.
This is a different problem from the one most vessel operators have prepared for. A single spoofing event that grounds a ship is a casualty investigation. Persistent regional denial of satellite navigation is an operating condition.
Jamming and Spoofing Are Not the Same Threat
The two get used interchangeably and they demand different responses.
Jamming denies the signal. The receiver loses lock, the position goes away, and the failure is obvious — alarms sound, the ECDIS drops to dead reckoning, and the bridge knows something is wrong.
Spoofing injects a false signal. The receiver keeps a confident lock on a position that is wrong. Nothing alarms, because from the equipment's point of view nothing has failed. The vessel's displayed position, and the position it broadcasts over AIS, are both fiction.
Jamming is dangerous. Spoofing is dangerous and quiet, which is why it has been the cause of the incidents that ended in contact with the seabed.
The Interference Now Spans Multiple Frequencies
Early interference tended to affect the civilian L1 band. Current Baltic interference spans L1, L2 and L5, which removes the assumption that a multi-frequency receiver will simply work around the problem. Multi-constellation and multi-frequency equipment raises the bar for an attacker; in the Baltic, that bar is being cleared.
Analysis of the disruption indicates it is not scattered opportunistic transmission but a tactically controlled network — coordinated, and adjusted over time. Planning around it as though it were background noise underestimates it.
The Consequence Nobody Plans For: Timing
GNSS is a positioning system, but it is also the maritime industry's clock. Satellite timing synchronises far more onboard than the chart display.
The Global Maritime Distress and Safety System depends on it. So do AIS transmission slots, some VDR timestamping, and synchronisation across a range of communications equipment. Interference that degrades GNSS therefore reaches into distress communications and rescue coordination — the systems a vessel needs precisely when a navigation failure has already gone wrong.
An operator who has thought about GNSS interference purely as a navigation problem has planned for half of it.
Where the Interference Is
The Baltic is the most documented case, but manipulation is being reported across the Black Sea, the Red Sea, the Gulf of Oman, the Eastern Mediterranean and the Persian Gulf. Several of these overlap with the world's busiest and most politically sensitive chokepoints.
For a fleet, that means GNSS interference has stopped being a regional briefing item for vessels on one route and become a standing condition on many. The practical question is no longer whether a vessel will encounter it, but whether anyone will notice when it does.
What Operators Can Actually Do
None of this is solved by better satellite receivers alone. It is addressed by cross-checking, by traditional competence, and by keeping a record of what happened.
- Cross-check position against independent sources. Radar fixes against charted features, visual and celestial bearings, and dead reckoning do not care what the GNSS constellation is transmitting
- Watch for the signature of a spoof. A position that jumps, a speed over ground that disagrees with speed through water, a heading that disagrees with the gyro, or a sudden implausible fix are all detectable as inconsistencies between systems even when no single system reports a fault
- Treat it as a reportable cyber event. GNSS interference sits squarely within maritime cyber risk management under IMO Resolution MSC.428(98) and the MSC-FAL.1/Circ.3/Rev.3 guidelines, and a documented record is what turns an anecdote into evidence for a flag state, an insurer or a casualty investigation
- Train for it. A bridge team that has practised navigating without satellite position handles the event; one that has not, discovers the gap during it
- Keep the timing dependency in the risk assessment, so the GMDSS consequence is understood before it is needed
The common requirement underneath all of these is the ability to see several onboard systems at once and notice when they stop agreeing with each other. A vessel where position, speed, heading and AIS are read off separate displays by different people at different times is a vessel where a quiet spoof goes unnoticed. Bringing those feeds into one view — which is what the NCoDE Engine does with the vessel's existing sensors, and what NCoDE SeaTwin renders visually — is what makes the disagreement visible while it matters.