Do I need a GPS?

Is a GPS just a fancy toy or a practical navigation tool? I see this question asked a lot with the answer “It is just something else to carry and a map and compass is better.” I carry GPS, map and compass all the time but the compass hasn’t seen the light of day in a long time.

Lets have a look at using the GPS in a practical way and see what the consensus is.

There’s a loch in the middle of the hills that I want to get to but there isn’t a path to follow. I have the map, compass and GPS with mapping software. With the map and compass I would set off, park the car, get a bearing from the compass to the loch from the map, and start walking. The mist comes down and I can’t see much around me that looks familiar. I check the map and compass every few yards but it gets harder and harder to fix my position. Even turning back is a problem as I have no real idea what path I took. The only thing to do is head downhill and hope for the best that I see a feature that I recognise or I can get a bearing on something with the compass. Sound familiar.

Now with the GPS, and before leaving home, I get the map of the area on the computer and set a waypoint for the start of the walk and one for the loch. I then have a look at the terrain and choose a route that uses the contours of the hill and misses any hazards that are showing i.e. plantations, rock faces, marshes etc.. Starting in Path mode and at the start waypoint I click at intervals along my intended route ending at the loch waypoint, this shows a path. I also mark any points on the path with waypoints that may be of interest or needed such as a river crossing, old building etc. I usually check the profile to see how it looks and the map to see if there is an alternative to a steep climb, there usually isn’t :) Once I am happy with the route I download it to the GPS, check that the route and waypoints have been saved and switch off. I then print out the map and laminate it, it saves taking a big paper map. I then check to see how long it should take to walk in using the information button in the mapping software; this is set up in preferences in the software. On reaching the setoff point and parking the car I switch on the GPS and, while getting the stuff ready, it picks up the satellites and locks on. I move to the map page on the GPS and check that I am at the start waypoint, or at least close to it, by looking at the co-ordinates shown and checking with the co-ordinates for the waypoint. Halfway up the mist comes down and I am in the compass/map situation described above except I have the GPS. I move to the map page and there is the path I downloaded. It is now a matter of walking on and checking that I am not deviating from it, unless I come across an obstacle that wasn’t shown on the OS map, and then it is just a matter of finding a way round it and returning to the virtual path and on to the waypoint at the loch. Any additional waypoints I have marked along the path I check their co-ordinates on the GPS against the map to make sure I am in the right place then carry on. The return journey is easier as all I have to do is click on Reverse Path and Follow Path and follow the path I walked up, not the one I made in the software, to get me back to where I started.

On returning to the house I download the active path from the GPS, not the one I saved from the computer, into the mapping software to see the route I had to take and how close it was to the one I set up. I then delete the original and save the new one, which should be more accurate. When I next go there I can download it back to the GPS happy in the knowledge that it will get me to the loch without any detours. While I am walking I can also mark waypoints at interesting features, a good campsite, marshy bits to watch when it is wet, etc. which I can look out for when next there without having to search for them by memory. Using other software I can tag any pictures using the GPS information and set them up to show on a map exactly where they were taken.

All in all the GPS has a lot more uses than a compass, including navigation.

©2008 Alexander Birrell
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