GPS satellite

MARAD Renews GPS Interference Warning to Industry

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September 22, 2020


The U.S. Maritime Administration has issued a renewed advisory to the maritime industry about instances of GPS interference that have been reported worldwide within the maritime domain.

U.S. Maritime Advisory 2020-016 says the interference has resulted in lost or inaccurate GPS signals affecting bridge navigation, GPS-based timing, and communications equipment, as well as satellite communications which may also be impacted.

According to the advisory, “multiple instances” have been reported over the last year from areas including eastern and central Mediterranean Sea, the Persian Gulf, and multiple Chinese ports.

MARAD provides guidance for crews to exercise caution when operating underway and prior to getting underway.

“The U.S. Coast Guard Navigation Center (NAVCEN) and NATO Shipping Center websites contain information regarding effective navigation practices for vessels experiencing GPS disruption. The information reaffirms safe navigation practices when experiencing GPS disruptions, provides useful details on reporting disruptions, and is intended to generate further discussion within the maritime community about other disruption mitigation practices and procedures,” the Maritime Advisory 2020-016 states.

This guidance also recommends reporting such incidents in real time; noting critical information such as the location (latitude/longitude), date, time, and duration of the outage/disruption; and providing photographs or screen shots of equipment failures experienced.

Contact Information: Maritime GPS disruptions or anomalies should be reported immediately to the NAVCEN at or via phone at 703-313-5900, 24-hours a day.

The NAVCEN information is available at:

The U.S. Transportation Command’s “Message for Industry” can be found at provides additional GPS interference information.


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