Windward has reported that the container ship MSC Antonia which ran aground in the Red Sea close to Jeddah Port, on May 10, likely did so due to GPS jamming.
According to Windward’s Maritime AI™ platform, analysis of the vessel’s data revealed distinct spoofing patterns that indicate the ship may have been misled by manipulated GPS signals. The incident occurred in one of the world’s busiest maritime corridors, heightening concerns among maritime authorities and operators.
The MSC ANTONIA ran aground near the Eliza Shoals, close to Jeddah Port, reportedly due to GPS jamming on May 10.
Windward’s Maritime AI™ visualized the spoofing patterns, part of a wider trend in the Red Sea.
We’re actively tracking this evolving threat. Stay tuned. pic.twitter.com/9VTBl0Ss5e
— Windward (@WindwardAI) May 12, 2025
Windward’s ongoing analysis has visualized a growing network of spoofing anomalies affecting commercial vessels transiting the Red Sea.
What is jamming?
Jamming is the intentional Radio Frequency Interference (RFI) with GNSS signals. It occurs when interference disrupts the signals at GNSS frequencies, preventing the GNSS receiver from detecting and processing the authentic signal. This happens because the strength of the jamming device exceeds that of the weaker GNSS signals received.
What is spoofing?
Spoofing involves transmitting a fake GNSS signal to deceive receivers, causing them to compute incorrect PNT data. This should not be confused with Automatic Identification System (AIS) spoofing, where altered or fabricated AIS data is transmitted to deceive AIS tracking systems regarding a ship’s identity, position, and other information.
Actions to take once GNSS outage/disruption is detected
Britannia P&I Club has advised the following steps if a GNSS outage/disruption is detected:
- Change the ECDIS position (both primary and secondary) and speed input to DR position and log speed
- Identify RADAR-conspicuous objects in the passage plan
- Begin manually plotting the vessel’s position using visual or RADAR means if near land
- Use tools such as RADAR parallel indexing and RADAR overlay on ECDIS to monitor the vessel’s position near land
- Confirm that the RADAR speed input is log speed, if not already set
- Other ships in the vicinity may also be affected by GNSS disruption; navigate cautiously and rely less on AIS information from other vessels
- Turn off AIS overlay on ECDIS if anomalies are observed in the AIS information of target vessels
- Advise the master of the situation. An extra deck officer may be required on the bridge for assistance
- Give wide room to any encountered traffic
- Consider arriving during daylight hours when approaching a port or area known for GPS disruptions
- Report any marine GPS signal disruptions to NAVCEN at https://www.navcen.uscg.gov/report-a-problem
- Alternatively, any GPS disruption can be reported to NATO at https://shipping.nato.int/nsc/page10303037
The Club has also recommended that shipowners and operators develop a response plan for GNSS disruption as part of their Safety Management System.
