Maritime navigation has made huge strides in recent years. One innovation in particular, GPS, has made navigation easier than ever. As a result, many mariners are now conditioned to expect excellent GPS performance.
That’s fine – to a certain point. But here’s a new twist. If a mariner relies solely on electronic charts for navigation, what’s the fallback position when their electronic navigation fails, or worse yet, is purposely jammed? On Jan. 19, 2016, the Coast Guard addressed this issue:
“This past summer, multiple outbound vessels from a non-U.S. port suddenly lost GPS signal reception. The net effect was various alarms and a loss of GPS input to the ship’s surface search radar, gyro units and Electronic Chart Display & Information System, resulting in no GPS data for position fixing, radar over ground speed inputs, gyro speed input and loss of collision avoidance capabilities on the radar display.”
According to a recent paper by The General Lighthouse Authorities of the United Kingdom and Ireland, GPS signals measured at the surface of the earth are quite weak. This means the system is vulnerable to interference and jamming, resulting in possible denial of service.
Electronic Navigation: Not under your control
It’s important to remember that the quality and reliability of electronic navigation is not entirely under the control of the mariner, no matter how diligently hardware/software upgrades are implemented:
“A GPS signal can be disrupted for a variety of reasons, including the illegal use of a GPS jammer. Indicators of GPS compromise include intermittent signal, no signal and/or incorrect signal.”
Several methods have been used to disable, confuse or otherwise render a GPS tracking device useless. One method is the use of a GPS ‘spoofing’ gadget – a device that sends a fake radio signal that overrides the GPS signal and reports a fake location. These are not only illegal, but can be dangerous to other GPS users.
Best practice: be equipped with both printed charts and GPS
Here at Oceangrafix, we agree with the Coast Guard. Electronic navigation is a great tool for mariners. But if the threat of jammed GPS exists, relying solely on electronic navigation is not a best practice by any means. Digitally updated, print-on-demand charts from Oceangrafix can’t be jammed, compromised, or otherwise manipulated. We believe that conscientious mariners will invest in—and use—both options to ensure safe navigation.