Setting GPS Waypoints - 5 or 6 Digits?
Q. I have been given a Garmin Etrex H for Xmas and am trying to plan a route by inserting GPS Waypoints as shown in Pathfinder walking books. Is this possible? The manual is so confusing! The GPS Waypoints in the Pathfinder books are 2 letters followed by 2 groups of 3 digits and yet the Garmin unit shows 2 letters followed by 5 digits. Can anyone help me with this?
Claire Jones, Macclesfield
A. GPSU is a good piece of software for copying routes and tracks to and from a GPS device. You can plot a route on a map - but even a keyboard is easier to use than buttons on a GPS
John Thorn, Cardiff
A. You are getting Grid References mixed up with GPS Waypoints.
A Grid Reference (e.g. SD 785 442) comprises two grid letters (which define a particular 100km x 100km square) plus a 6 figure number (which defines a particular 100m x 100m square within that larger square).
A GPS Waypoint (e.g. SD 78500 44200) comprises two grid letters (which define a particular 100km x 100km square) plus a 10 figure number (which defines a particular 1m x 1m square within that larger square).
There is little point entering 6 figure grid references into a GPS Device since they are not accurate enough to be useful. Furthermore, entering GPS Waypoints into a GPS (Garmin or otherwise) by hand is long-winded, tedious and prone to mistakes. If you want to use your GPS for walks then you should download the accompanying GPS Waypoint Data file supplied with go4awalk.com walks and get the most out of your Christmas present.
For more information on national grid letters see The National Grid.
For more information on giving a grid reference see Giving a Grid Reference.
For more information on GPS Waypoints and GPS Systems see GPS for Walking and Hiking.
For walks with downloadable GPS Waypoints see Walks with GPS Waypoints and GPS Data.
Once you get the hang of it your GPS Device will become a useful and valuable Navigational Aid. Just make sure you continue to take your map and compass with you so you can still find your way home if your batteries fail or you cannot pick up any satellites (which happens from time to time).
Hope this helps.