What map reference should we give the Mountain Rescue?

Q. Walking with a GPS and ord.map. We need to call for help, question, must our position be lat long or would our gps mvt7smap reference be ok, die do we have to change our gps settings to obtain lat long reading.

John Harrison, Cleveland

A. Keep it simple and give the Ordnance Survey Map Grid Reference to the emergency services. They will understand it and be able to find you quickly and efficiently - particularly important if it is dark. You can either get this grid reference from your GPS Device if you have one - and give the map reference as a 12 digit reading (i.e. to the nearest metre*) - or simply read it off on your OS Map - which you must always have with you (whether you use GPS or not) and give the map reference as a 8 digit reading (i.e. to the nearest 100m).

If you are not sure how to give a grid reference - or just want a refresher - see Giving a Grid Reference

*Actually you can only rely on a GPS Device being accurate to about 25m even though it gives readings to the nearest metre.

For more information on GPS Waypoints and a free sample file - sign up for the go4awalk.com HTML Newsletter. Full details on how to access and download some free walks that include downloadable GPS Waypoint data, links to the software and a cable vendor - are available in the current issue.

For more general information on GPS and GPS Devices - see

For fellow user Questions and Answers about GPS and GPS Devices - see