The United States raises concerns with the International Maritime Organization over the surge in satellite navigation signal disruptions

I have mentioned this several times before: GPS signals (and GNSS more broadly) are essential for the safe day-to-day operation of the maritime sector. We have already discussed the risks associated with spoofing or jamming of these signals, the specific risks related to autonomous maritime vehicles, as well as several real-world examples, including incidents in the Persian Gulf.

On March 10, 2020, the United States formally raised concerns with the Maritime Safety Committee of the International Maritime Organization (IMO) regarding the increasing number of disruptions affecting GPS and GNSS signals. The submission, available here, calls on the IMO to urgently address cases of jamming and spoofing that threaten the safety of ships and seafarers.

After recalling several known intentional interference events in the Black Sea and the Eastern Mediterranean between 2016 and 2018, which affected navigation in international waters and in areas with heavy maritime traffic, the document highlights the almost systematic nature of these incidents. It refers in particular to research showing that during a one-year ocean voyage, each cargo transit between Europe and Southeast Asia encountered at least one instance of GNSS interference.

Such intentional disruptions violate international regulations, notably the International Telecommunication Union Radio Regulation 19.2, which prohibits transmissions whose origin is false or misleading.

In response, the United States is asking the IMO to issue a circular:

• reminding IMO member states not to conduct such operations except when strictly necessary for security reasons;
• requesting that member states take the necessary measures to prevent interference with GNSS satellite signals and inform mariners about the periods and areas where such disruptions may occur.

Beyond the publication of a circular, it is also reasonable to expect that prevention, detection, and resilience mechanisms—such as CRPA antennas and other technologies—may eventually become mandatory aboard ships.