Satellite positioning system interference threatens maritime navigation safety, urging a return to traditional methods in conflict zones.
Interventions targeting satellite-based positioning systems in international maritime transportation continue to pose significant risks to the safety of navigation for vessels. Particularly, activities such as GPS jamming and spoofing observed in conflict zones have reopened discussions regarding the dependency of ships on electronic navigation systems.
In the maritime sector, it is emphasized that traditional navigation methods and independent position verification systems should be maintained to ensure that vessels can continue their navigation in the event of GPS signal loss or unreliability.
Warning from a Danish researcher to the maritime sector
Kian Bostani Nezhad, a doctoral researcher at the Technical University of Denmark (DTU), stated in an interview published on October 27 in the Maritime CEO section of Splash247 that global navigation satellite systems (GNSS) can no longer be considered a reliable primary navigation method under all conditions.
Nezhad noted that GNSS interventions have become a persistent problem and that the maritime sector should view satellite positioning as a tool that supports other navigation methods.
SAT-JAM system detects satellite interventions from space
The online platform SAT-JAM, developed by Nezhad and launched in September, monitors interventions targeting satellite navigation systems from space.
The system maps distortions in positioning signals using publicly available data obtained from Europe’s Sentinel satellites.
The research found that satellites operating at altitudes of approximately 400 to 600 kilometers above the Earth can also be affected by navigation signal interventions.
The findings reveal that the signal issues faced by vessels in regions such as the Baltic Sea and the Black Sea are not limited to receivers on the water's surface.
Four tankers in the Black Sea appeared in Peru
One of the incidents illustrating the scale of interventions against satellite navigation systems occurred in the Black Sea.
In September, it was observed that the AIS position data of four tankers indicated they were located in Lima, the capital of Peru, over 12,000 kilometers away from their actual positions.
The incident, detected by the Worldwide AIS Network, revealed that an AIS receiver in Varna, Bulgaria, recorded 27 erroneous position reports from the four vessels.
An average of 5,131 interventions per day over three months
According to data from maritime intelligence company Windward, an average of 5,131 GPS jamming incidents was recorded daily in the third quarter of 2026. During this period, over 124,000 vessels were affected by these interventions.
The UK Maritime and Coastguard Agency (MCA) also warned ship operators in its MGN 719 guidance published in October to prepare for conditions where satellite navigation is not reliable.
The agency highlighted that GPS-related issues could affect not only electronic charts but also systems such as AIS, ECDIS, autopilot, and dynamic positioning.
Radar and traditional navigation methods regain importance
The British maritime authority recommends that ship operators identify equipment dependent on satellite data, establish procedures to detect signal interventions, and ensure that crews receive regular training on alternative navigation methods.
These methods include position determination using radar, visual bearings, celestial navigation, and computational navigation utilizing compass data and log readings.
The Japanese classification society ClassNK also announced on October 23 that it has created a new class notation for vessels equipped with systems capable of detecting GNSS signal interventions. This initiative aims to facilitate the detection of interventions and alert bridge personnel.
Source: SeaNews Türkiye
