Global Navigation Satellite Systems (GNSS) and the Automatic Identification System (AIS) have become critical tools in modern maritime navigation. However, as their reliance grows, so do the threats they face, reports the Shipowners Club.
Jamming and spoofing—both deliberate and accidental—pose significant safety and operational challenges to vessels worldwide. These threats can lead to ships being misled about their true position, disabled navigation systems, or false vessel tracking information, increasing the risk of collisions, groundings, and loss of situational awareness.
What Are Jamming and Spoofing?
Jamming occurs when a signal is deliberately overpowered or blocked, rendering GNSS or AIS data unavailable or unreliable. Spoofing, on the other hand, involves broadcasting false signals that mimic legitimate GNSS or AIS data, misleading receivers about a ship’s position or identity. Spoofed signals can cause vessels to drift off course unknowingly or display false positions on navigation systems—threatening not only maritime safety but also national security.
Real Incidents Underscore the Danger
Numerous regions have reported increased incidents of GNSS and AIS interference, including the Baltic Sea, Red Sea, Black Sea, and Eastern Mediterranean. In some cases, ships have experienced sudden “jumps” in position on digital charts or unexpected deviations in course and speed. A notable example includes a container ship that reportedly ran aground after being misled by spoofed GPS signals. Such cases highlight how easily compromised navigation systems can lead to severe consequences.
International Attention and Regulatory Push
In response to the growing concerns, international organizations such as the International Maritime Organization (IMO), the International Telecommunication Union (ITU), and the International Civil Aviation Organization (ICAO) have expressed collective alarm. They have urged member states to adopt stronger reporting mechanisms, protect satellite frequencies, and invest in systems that can detect and respond to interference. These warnings highlight that GNSS interference is no longer a rare occurrence but a systemic risk requiring coordinated action.
How Ships Can Detect Interference
Detecting spoofing or jamming is not always straightforward. However, there are telltale signs that bridge crews can watch for. Sudden jumps in position on electronic charts, discrepancies between radar and GPS data, erratic changes in speed or heading, and mismatched depth readings can all signal potential interference. In such situations, it is critical for crews to fall back on traditional navigation techniques, such as dead reckoning and radar plotting, and to use alternative sources of positional data where possible.
Tools and Technology for Resilience
New technologies are emerging to help ships resist GNSS and AIS interference. Modern gyrocompasses, for instance, provide accurate heading and speed data even in the absence of satellite input. Some vessels are now equipped with multi-frequency GNSS receivers that can detect and reject spoofed signals. Additional systems use inertial navigation to maintain course when external inputs are lost. These tools are proving vital for maintaining navigation accuracy in high-risk zones.
Strengthening Operational Preparedness
Beyond hardware, shipowners and operators are advised to incorporate GNSS interference protocols into their Safety Management Systems (SMS). Bridge teams should be trained to recognize spoofing and jamming indicators, respond appropriately, and switch to manual or alternative navigation systems when needed. Regular drills and scenario-based training can ensure crews are prepared to act quickly and safely in the event of interference.
The Way Forward
Jamming and spoofing are no longer fringe threats—they are growing realities in many of the world’s busiest sea routes. The maritime industry must respond with a multi-layered strategy combining advanced technology, crew training, operational procedures, and regulatory coordination. Only through such a comprehensive approach can the integrity of maritime navigation be preserved, ensuring safety, security, and confidence at sea.
Did you subscribe to our daily Newsletter?
It’s Free Click here to Subscribe!
Source: Shipowners Club
