Sat nav explored

Satellite navigation (sat nav) using the Global Positioning System (GPS) has been one of the boom areas of the last few years, and now barely a week goes by without tales of someone plugging in their sat nav, leaving their brain at home and ending up stuck in a river.

For most of these people, sat nav is all about getting them from A to B with the minimum of hassle.

While the low price and improved performance of in-car sat nav has brought it to the attention of many who’d not heard of it before, the technology is certainly not new. Whether it’s sailing, skiing, cycling, running, walking, orienteering, or something more pedestrian, there’s almost certainly a way that GPS technology can be used.

Pi in the sky
While in-car navigation is the most visible face of GPS, it certainly wasn’t designed for that; if you’re unfamiliar with the technology, it’s essentially a constellation of satellites orbiting the earth, broadcasting data. By knowing how the satellites orbit, and seeing which ones are ‘visible’ in the sky at a particular time, a GPS receiver can calculate its position on the surface of the Earth using basic trigonometry.

The navigation that we take for granted in our cars is just a lot of clever maths. Throw in some maps and planning software, and you have the basis of the sort of navigation system that we have in our cars today.

But, of course, cars aren’t the only area where you can benefit from knowing where you are at any given time. Whether it’s simply replacing an old-fashioned triangulation on a map when you’re walking, or keeping track of the top speed for a cyclist, there are dozens of areas where the information provided by GPS can prove useful.

In the past, sat nav wasn’t a cheap technology, and early units could prove confusing to those who weren’t experienced map readers. Thanks to the boom in car sat nav, GPS receivers are cheaper than ever now, and over the next few pages we’ll aim to give you an idea of the range of satellite navigation products available in the shops now.

A life on the ocean wave
One of the most common original uses of GPS was for sailing and other maritime pursuits, where knowing your exact position is a highly skilled art, with few landmarks to help. While the original sat nav systems sometimes provided little more than a precise position so that you could find yourself on a traditional chart, modern systems can provide much more information.

If you’re looking for a sailing equivalent of an in-car sat-nav, they’re called chartplotters in the jargon. Products such as Garmin’s GPSMAP 276C can be used for route-planning on land and plotting a course on the water too, but at about £480 this is not a cheap option. Fish finders typically include sonar and many units are available with extra accessories.

Navman’s Sport Tool M300 is specifically designed for windsurfers, providing compass heading, as well as time and distance recording, in nautical miles. There’s an automatic timer and a programmable speed target zone, and you can recall the details of the past fifty runs.

You’ll find the Sport Tool range on Navman’s website, but it’s well hidden. The M300 costs about £110.

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