GPS Disruptions Off the California Coast Warn of Risks to Global Shipping

On January 29, 2026, GPS signal disruptions were reported near the Port of Long Beach, raising concerns among maritime vessels and aviation. Seven vessels approaching the port reported GPS malfunctions via VHF channel 14, while aircraft over the Channels reported similar issues.

According to NOAA, anomalies in the signal-to-noise ratio were recorded at CORS stations for approximately one hour, affecting waters approaching the ports of Los Angeles and Long Beach. These events occurred under clear weather conditions and good visibility.

AIS signals from at least seven vessels showed sharp positional changes, indicating possible GPS spoofing. One vessel completely ceased AIS transmission for nearly an hour, likely due to an invalid GPS solution.

Although all vessels involved ultimately entered the port successfully, the situation could have created dangerous conditions, especially within the traffic separation scheme where reliable navigation solutions are critically important.

On February 4, six days after the incident, it was noted at the Los Angeles and Long Beach Port Safety Committee meeting that the likely cause of the GPS disruptions was a test conducted at the Point Mugu Sea Range.

While GPS testing is a common practice, such widespread disruptions are relatively rare. Available data does not provide complete certainty, but it is suggested that the source of the anomalies was the PMSRCA test 26-02.