Back in 1957, US scientists tracking the first Russian satellite, Sputnik, noticed that they could use the Doppler effect to work out exactly how far away it was. Since they knew where they were they could use that information to work out where the satellite was, and from there it’s a small step to realizing that if you know where the satellite is then you can work out where you are. It wasn’t until 1978 that the US launched the first experimental Earth-positioning satellite, and it was 1993 before the array of 24 satellites, which were needed for accuracy and global coverage, were ready for use. Now, in 2006, we can finally use this multibillion-dollar plethora of technology to calculate how far we jogged this morning and the best route to the liquor store, with the US government spending $400 million a year to keep our jogging records accurate!



Of course GPS, as the Global Positioning System is generally known, does a great deal more than keep track of joggers and provide directions to lost drivers; its primary applications are military, because knowing where you are in the middle of a battle is a great deal more important than knowing that you’re slacking on your exercise routine. Anyone who has spent time on a yacht outside a harbour will be familiar with the GPS accurately reporting where they are, and anything but the smallest dingy is now equipped with GPS navigation as standard. Indeed there is now a whole generation of pilots to whom trying to navigate without GPS is as alien as trying to maneuver without a rudder! To get an accurate fix the GPS equipment needs to receive signals from a few satellites (three at a minimum and more for greater accuracy) and do some really complicated mathematics; the whole process taking up to a minute, particularly in built-up areas where the sky may not be so visible. The result is a longitude, latitude, and an altitude (the latter rarely being useful on a yacht) accurate to within a few meters (and often better).

While a rough location is good enough for most of us – particularly when at sea, to some a difference of a meter or two can mean the difference between glory and ignominy. When yachts line up to race they want to be as close as possible to the starting line, but crossing it means disqualification, so knowing precisely where you are can be the key to the race. Team Suunto is a four-man racing team sponsored by the manufacturer of a GPS wristwatch, a technology on which they rely to give them the edge at both the start of the race to get them as close to the line as possible, as well as after the race when they can generate charts showing them exactly the route they took with a view to improving their performance for next time.

However, knowing where your yacht is can be even more useful when you’re not on board. Some security systems are now coming with GPS fitted in so that the yacht can sound an alarm if taken outside a predetermined area, in addition to normal theft-detection features. VoiceAlarm makes a system that will call your cell phone, sound a siren, or make a radio call when your yacht is taken outside of a circle that you define. This obviously has applications beyond anti-theft because you could charter with limited roaming, or let the children loose knowing that they can’t go too far (as though you’re going to let the children loose with your yacht!). If a yacht is also equipped with satellite communications then it can regularly report its location for fleet tracking or after-theft recovery, and with GPS equipment getting so tiny it’s becoming very difficult for thieves to find and disable such equipment.

GPS is only going to get smaller, with improvements in antenna and decoding chip design. Several companies make wristwatch GPS, though early models were more Terminator than Bond, and some required a separate antenna strapped to the upper arm that dented their style value considerably. Garmin is a leader in GPS equipment, and their Forerunner 305 is about as close as you can get to a useful wrist-mounted GPS, though it is aimed firmly at the jogging crowd with its heart-rate monitor and ability to “seamlessly transition between sports,” and still is hardly a Rolex in design terms. Rakon, a New Zealand–based company, has developed a GPS receiving chip that is smaller than a fingernail, so better styling should be on the way. Pretty soon all mobile phones will need some form of location tracking for the emergency services, but GPS isn’t the only game in town.

The Russian Glonass operates in much the same way as GPS, but due to the state of the Russian economy it was reduced down to eight satellites, which is too few to be used. It is now being rebuilt, but is mainly for military applications. The military roots of GPS worry many countries, and the ability of the US military to shut down civilian access to the network without warning restricts its application where reliability is key, even though they would be unlikely to do so. Last week saw the first test transmissions from Galileo, the European equivalent to GPS. Galileo will offer slightly greater accuracy than GPS, particularly at extreme latitudes, but primarily it will be a civilian system with no military involvement or control.

It will even be possible to combine information from GPS and Galileo for even greater accuracy, so while deciding where you want to go will remain as difficult as ever, at least you can be increasingly confident that you’ll know when you get there.