Coastal States warn of safety risks increased by GNSS interference

The coastal States of the North Sea and the Baltic Sea have called for international action in response to growing navigation system interference and the risks to maritime safety.

New safety challenges are emerging due to the growing incidence of GNSS interference in European waters, particularly in the Baltic Sea region. These disturbances degrade the safety of international shipping and place all vessels at risk. As highlighted by a study conducted by Gdynia Maritime University and GPSPATRON, there is an urgent need to establish a comprehensive territorial GNSS interference monitoring network along the Baltic Sea coast.

According to the joint letter published on 26 January by the Coastal States of the Baltic Sea and the North Sea with Iceland, the accurate and uninterrupted functioning of Global Navigation Satellite Systems (GNSS) is not a technical luxury, it is a critical safety requirement.

GNSS signals support not only ship navigation but also precise time synchronization vital for systems such as the Global Maritime Distress and Safety System (GMDSS). Disruption of these signals is a risk to the safety and reliability of maritime transport.

Equally vital is the integrity of the Automatic Identification System (AIS), which plays a key role in traffic coordination, enhances situational awareness and emergency response. Spoofing or falsifying AIS data undermines maritime safety and security, increases the risk of accidents, and severely hampers rescue operations.

The States call upon the international maritime community and national authorities to:

1. Recognize GNSS interference and AIS manipulation as threats to maritime safety and security.

2. Ensure vessels have adequate capabilities and properly trained crew as required by international conventions to operate safely during navigation system outages.

3. Cooperate on the development of alternative terrestrial radionavigation systems which may be used in place of GNSS in the event of disruption, loss of signal or interference.

Maintaining trust in maritime navigation requires more than technology – it demands responsibility, transparency, and decisive action. It must be ensured that seas remain safe, including when systems fail or face disturbances.

[…] We stress that the full and consistent implementation of the IMO regulations is fundamental to ensuring maritime safety, the smooth functioning of shipping, and the protection of seafarers and the marine environment, especially in the new emerging situations affecting safety at sea, such as the increasing use of shadow fleet vessels to circumvent international sanctions. 

The signatories highlight the need for all vessels exercising freedom of navigation to fully comply with international maritime law, including UNCLOS and key IMO conventions such as COLREG, SOLAS, MARPOL, STCW and related resolutions.

As further explained, vessels must sail under a single flag, carry valid certification and insurance, operate under an approved safety management system and meet flag State compliance and oversight requirements. Ships must also ensure proper watchkeeping, maintain AIS and LRIT systems and provide required information to ship reporting systems and maritime authorities, including VTS.

Furthermore, vessels are required to follow mandatory routing measures and local navigation restrictions, report pollution incidents and carry approved emergency and pollution response plans. Ship-to-ship transfers are regulated, requiring approved plans and prior notification to coastal States and must not be conducted without authorization.

The issue has again come to the forefront in 2025, as incidents of satellite navigation spoofing and jamming in the Baltic Sea region have increased significantly compared with previous years.

While precise figures are not available, multiple indicators suggest that both the scale and persistence of such interference have grown markedly, according to RiskIntelligence. Automatic Identification System (AIS) data further support this assessment, showing particularly heavy spoofing activity in areas around Kaliningrad and St. Petersburg.

The Coastal States of the Baltic Sea and the North Sea with Iceland: Belgium, Denmark, Estonia, Finland, France, Germany, Iceland, Latvia, Lithuania, the Netherlands, Norway, Poland, Sweden, the United Kingdom.

We have consistently kept interference and the related risks high on our agenda in international forums. Our particular concern relates to vessels and crew that do not have the capabilities for winter navigation and are vulnerable to GNSS interference. We want to ensure that all countries are committed to international conventions and are adequately prepared for incidents when operating in the Baltic Sea region.

source : safety4sea