Technical Circular No. 007 | 2017

Subject: Global Navigation Satellite System Disruptions.

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  • In recent past, some vessels from a non US port lost GPS signal reception which caused the loss of GPS input to various equipment like ship’s surface search radar, gyro units and ECDIS.
  • This resulted in no GPS data for position fixing, radar over ground speed inputs, gyro speed inputs and loss of collision avoidance capabilities on the radar display.
  • Considering above, the United State Coast Guard has issued Marine Safety Alert 01-16 (copy attached) to address the potential detrimental impact to navigation caused by GPS interference or jamming and the importance of understanding how vessel or facility equipment could be impacted by the loss of a GPS signal. This Safety alert also provides guidance on handling and reporting these disruptions.
  • Positioning signals can be impacted by interference from both natural and human-made sources. Most of the time interference like reception issues is due to bad installations, poor antenna positioning or faulty equipment.
  • USCG has advised commercial operators to report immediately to U.S. Coast Guard Captain of the Port, District Commander or Vessel Traffic Center as soon as possible in case navigation or other equipment onboard is impaired due to disruption or interference.
  • All operators are required to be aware, vigilant, and immediately report GPS disruptions to the U.S. Coast Guard Navigation Center (NAVCEN)
  • Reporting a disruption or other navigation hazards or aids to navigation outages can be done preferably by electronically or phone call to the NAVCEN (703-313-5900), 24 hours a day.
  • Ship owners / operators and masters are advised to be guided by above.


  1. United States Coast Guard marine safety alert 01-16 regarding Global Navigation Satellite Systems Disruptions.


This Technical Circular and the material contained in it is provided only for the purpose of supplying current information to the reader and not as an advice to be relied upon by any person.
While we have taken utmost care to be as factual as possible, readers/ users are advised to verify the exact text and content of the Regulation from the original source/ issuing Authority.


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