We all take our GPS for granted: flick a switch and sail. But there are several causes of GPS failure that you have no control over, and some may be on the rise. It's easy to rely on this technology as a sole mode of navigation, but doing so puts you and your vessel in possible danger from a wide variety of malfunctions. A handful of factors out of a sailor's control can force a GPS navigation system to fail. Are you aware of the following potential "outside forces" that can affect your GPS systems?
- Geomagnetic storms alter the ionosphere (the outer most layer of the atmosphere), and cause the GPS satellite signal to flicker, thus making readings inaccurate.
- Solar flares degrade reception of the GPS signal, not to mention that the earth is moving into another
"Solar Maximum", meaning more frequent and lengthy interruptions of the GPS signal due to solar flares.
- A GPS signal may not be available due to degradation of GPS constellation, or the military employing "Selective Availability" in certain geographic regions.
- Man-made interference from malfunctioning marine TV antennas can wreak havoc with your GPS system. You probably thought that antennas just receive signals, but they can also emit a signal that can mess up your GPS.
- Of course there is also the possibility of battery and/or power failures that can affect onboard GPS systems. This, like the other factors above, can only be anticipated … but not prevented.
If a GPS failure were to occur while your vessel was on autopilot, without a truth-check with your other onboard devices and an up-to-date nautical chart, the results could be serious. Or worse yet, if you were to experience a complete GPS failure while trying to navigate in less-than-perfect conditions - and you don't have a nautical chart to help triangulate your position - you may be lost at sea. At OceanGrafix, an official partner of NOAA and of USPS (United States Power Squadrons), we are constantly reiterating the importance of carrying up-to-date, full-size NOAA paper charts. Click here to learn about our unique print-on-demand NOAA charts, and how you can receive free e-mail notifications of the latest official NOAA "Editions" of the charts you carry. Safe sailing!
