All about GPS

Where does GPS technology fit in?

There are various ways which you can use GPS technology:

  • Before a walk, to plan the walk on a screen, working out not only the route, but also determine its length, total ascent and descent, and rough time without stops
  • During a walk, either following a route you have pre-designed, or else simply checking where you are
  • After a walk, comparing what you planned with what you did, and then saving the walk for future reference or to pass on to someone

Limitations of GPS

Whether you are using a dedicated GPS (like a Garmin) or an app on your phone, the first issue of which you need to be aware is that like any electronic device they can malfunction, be lost, break or simply run out of battery power. The precaution you can take against the last of these issues is always to carry spare batteries, or a battery pack. The problem with using your phone as a navigation device is that it is also your best emergency rescue device. If you have an accident towards the end of the day (which is when most accidents happen – just ask any Mountain Rescue team) and have been navigating using your GPS for all that time, you may well have problems if you need to maintain contact with the emergency services. Using the GPS on your phone gobbles up power at a alarming rate as it is communicating with satellites 20,000km away, as well as phone masts.

Secondly, a GPS may be excellent at telling you where you are at any one moment, where you have come from and where you are going, but it tells you NOTHING about the terrain through which you will be going unless you can read map symbols, especially contour lines.

This links with my third reservation, namely that someone who becomes a slave to the small arrow on a GPS is not paying attention to the many other features in the landscape which allow you to locate yourself. Woods, fields, fences, valleys, ridges and rivers all locate you firmly at an exact point within a large area.  They are all shown on your GPS screen, but you are so fixated on the small arrow you simply don’t see them or realise their significance. Your relationship is not with the landscape, but with an arrow.

Fourthly, there are a couple of issues with screens. On a dedicated GPS the screen is relatively small compared to that of a phone. And obviously the area covered by a GPS screen is tiny compared to that covered by the relevant map. The problem with mobile phone screens is that they are often hard to read in bright sunlight. This is not an issue with dedicated GPSs, and the brighter the sun, the more visible a paper map is.


When it’s really useful on a walk

Even the best navigators are confused at times about where they are. This is especially the case in flat woods with no obvious other features, and where the paths on the ground bear little resemblance to those on whatever map you have. In such instances turning on your GPS can immediately set you right. 


Should I buy a dedicated GPS?

My advice on this is try a relatively inexpensive app (eg Ordnance Survey) before you shell out hundreds of pounds on a GPS.


What is the best navigation app for a phone?

There are many, but in my opinion the best for the UK is that provided by Ordnance Survey. For about £35 a year you have access to all their most up to date digital mapping, so you will never need to buy a physical map. Furthermore you can create pdfs of sections of maps at whatever scale you want and print them out to scale. You can create a library of your walks and access aerial and 3D views of them. There are other apps which give you access to OS’s maps, but they are not always up to date and don’t allow you to print out the map. OS’s phone app allows you to save digital mapping to your phone so you don’t have to use any data when accessing the maps on a walk. This means you don’t need internet access to view a map when out on a walk. And if you have any questions you can use their online chat service.

Can you access OS digital mapping for free?

Yes, but not, to the best of my knowledge, linked to GPS. North and Mid Cheshire Ramblers’ website ( have OS digital maps available under their ‘Maps and Route Planner’ – ‘See Map / Plan Route’ tabs. They are not the most up to date and I can’t see how they can be printed out to scale (in any case you might be infringing copyright if you do), but the site does allow you to plan walks and create a GPS track, which you can send to your phone / dedicated GPS.