Imagine that you are driving through Birmingham when, suddenly, your ‘Sat Nav’ starts to tell you that you are in Manchester.  In such a situation, you would quickly realise that the GPS had gone haywire; however, if you were in a ship, out of sight of and beyond radar contact of land, it would not be immediately obvious that you were being given false positions.  If you are one of those people who depend heavily on the GPS and believe that it will never let you down, then you might be in for a nasty shock.  The New Scientist reports that Russia may be experimenting with methods of interfering with GPS signals and that these methods could quite easily be copied by other organisations including rogue nations and terrorists.

Sebastian Anthony talks of our terrifying reliance on GPS and our need to develop back-up systems.  Imagine the devastating effects that a GPS failure would have on land, air and sea navigation, air traffic control, communications, power grids, radar, defence and a host of other systems very few of which have ‘back-ups’ in place.

Things can easily go wrong with the GPS even without malicious interference. For example, magnetic storms can put power grids out of action, blank out communications systems including the internet and destroy satellites (including those that serve the GPS).

I warned of these dangers on this website in 2008 with my post Could The GPS Fail when I made the point that fortunately, when it comes to navigation at sea, we do have a back-up system; a system which has been tried and tested over hundreds of years; of course I speak of Astro / Celestial Navigation.

It is all very convenient to find our way by GPS but what would we do without it when we are far out to sea where there are no roads, signposts or other landmarks to guide us? Prudent navigators keep up their skills in astro / celestial navigation by taking at least one astro fix a day when on passage. The reason they do this, is not only to practise their skills but also to keep a check on the GPS. In fact, many experienced yachtsmen and women do not employ GPS at all when on ocean passage but rely solely on their skills in astro / celestial navigation instead.

If Astro / Celestial Navigation is new to you or you just want to brush-up your skills, you might be interested in the following.