GPS Jamming in Contested Waters Demands an All-Source Operational Maritime Picture

At a Glance

• GPS jamming touched 124,235 distinct vessels worldwide in Q3 2026, and the Black Sea alone accounted for 30% of it.
• Jamming is an area-level event that corrupts the reported position of every ship in the zone.
• AIS spoofing is a choice made by a specific vessel, and its behavior is what gives it away.
• All-source operational intelligence keeps the picture intact by cross-checking sources when one of them fails.
• The picture has to plug into the national C2 and mission systems navies already run.

GPS Jamming Has Become Routine in Contested Waters

Operations in degraded environments are no longer a planning scenario. For anyone responsible for a maritime operational picture, they are already the operating condition in much of the water European navies patrol.

GPS jamming touched 124,235 distinct vessels worldwide in Q3 2026, up 11.7% on the previous quarter, according to Windward’s Q3 2026 maritime risk report. September was the busiest month of the year, and the Black Sea alone accounted for 30% of the jamming Windward observes worldwide.

GPS Jamming Is an Area Problem, and It Changes What Every Vessel Reports

GPS jamming is an area-level event. 

Interference degrades satellite navigation signals across a zone, and every receiver inside it is affected, whatever the ship and whoever owns it. Because a vessel’s AIS position comes from its own satellite navigation receiver, every ship in that zone can end up broadcasting a position that is wrong. 

In August 2026, Windward found that 393 of the 642 transits logged through the Strait of Hormuz, 61.2%, never happened. Jamming corrupted AIS positions and produced transits that no ship made. Windward’s Q2 2026 risk report counted 3.35 million false ship-to-ship meetings generated by GPS jamming worldwide since late February 2026.

One case from May shows how this looks in the data. 

Two tankers off Fujairah appeared to meet. Both vessels’ AIS positions had jumped onto the same two spoofed coordinates. At the same instant, one of them was reportedly meeting hundreds of other ships at the same point. No meeting had happened. Read as vessel behavior, it would have been a false lead. Read as an area event, it was filtered out.

That distinction matters for a navy. A watch officer who reads jamming as vessel behavior chases ghosts and suspects ships that did nothing wrong. One who ignores jamming altogether lets real activity hide inside the noise.

AIS Spoofing Is a Vessel Choice and Behavior Exposes It

AIS spoofing is a different problem. It does not happen to a ship because of where it sails. It is a choice made on a specific vessel to broadcast a false position or a false identity.

A case from September shows the difference. The Philippine Coast Guard accused a Chinese-flagged research vessel of spoofing its location while it held station about 38 nautical miles northwest of Itbayat in Batanes, over cable corridors in the Luzon Strait.

According to the coast guard, the vessel’s AIS showed it moving from the coast of Xiamen to a location off Papua New Guinea on the same day, and its behavior was consistent with marine scientific research rather than transit. Windward data showed the vessel’s AIS destination field reading “TOWING 1NM CABLE”. 

The Chinese Embassy in Manila said the ship was conducting normal operations in waters under Chinese jurisdiction.

No area effect explains a reported track like that. The broadcast and the vessel’s physical presence disagreed, and the disagreement belonged to one ship.

Identity spoofing works the same way. The IMO’s list of falsely flagged ships reached 613 at the end of Q3 2026, and the list includes 27 fraudulent registries. A false flag is broadcast by choice.

Behavior is what exposes it. A reported track that jumps an impossible distance, a position no other sensor confirms, a destination field that reads like survey gear, or a flag no registry recognizes all point at the vessel rather than the area. Separating that from jamming is the first analytical step, and it decides whether a ship is treated as a suspect or a bystander.

All-Source Operational Intelligence Holds the Picture When One Source Fails

No single source survives a degraded environment on its own. AIS fails under jamming and misleads under spoofing. Satellite imagery has revisit gaps and weather limits. RF detection confirms that an emitter is present but not always who it belongs to. What holds is the combination.

All-source operational intelligence fuses AIS with whatever sources the mission requires.

 That can mean SAR and EO satellite imagery, RF detection, dark vessel detection, registry and ownership data, years of behavioral history, or any other source that sharpens the picture. When one input degrades, the others check it.

Windward’s Q2 2026 risk report made the same point for conflict zones — positional data should be treated as adversary-influenced until independently verified, and telling a deliberate evader from a ship caught in interference means correlating the gap with imagery, ownership, and voyage behavior.

The result is a picture an operator can trust because it does not depend on any one feed being honest.

Integration Matters More Than Another Dashboard

Navies do not need another screen. They need the picture inside the systems they already run, from national C2 to the mission and combat management systems that shipbuilders and integrators deliver.

That makes integration the real test in procurement. A capability that demands rip-and-replace, or adds a separate dashboard that watch officers have to check alongside everything else, rarely survives contact with an operational workflow.

Windward’s intelligence is built to be consumed outside its own interface. Its API is GraphQL-based, so integrators can request exactly the fields a mission system needs. Webhooks push events such as risk score changes and alerts on vessels of interest into existing systems as they happen. Risk indicators are traceable to the evidence behind them, so an assessment stays auditable once it leaves the platform, and the API is designed to sit alongside a customer’s own data rather than replace it.

For navy program and acquisition managers, that means the capability can arrive through the mission and combat management systems their shipbuilders and integrators already deliver, rather than as a new system to procure, accredit and support. 

For the shipbuilders and system integrators themselves, it means adding fused maritime intelligence to what they offer a navy without building or maintaining it in-house.

Deployment models and data residency requirements differ by country and programme, and they are worth raising early in any conversation.

Bring Your Degraded-Environment Questions to Hall 6

GPS jamming is not a scenario to plan for. It is the condition navies already operate in, and AIS spoofing rides on top of it. The answer is a maritime picture built from all-source intelligence that holds when one source fails and arrives inside the systems navies already run.

Windward is at EURONAVAL through November 6 in Hall 6, booth J128. Book a meeting to see how the picture holds up in contested waters.

Written by Maya Romi, Windward Senior Content Manager.