NSW Nordic Ski Club
GPS - The GPS Issue
Back to Archive index
Dear Editors,
With regard to the use of a GPS I stand by my statement that "a compass is not essential in practice but must be carried" but I appreciate John Garrett's comments so that there is no confusion. The extract which was part of the navigation information on the KCros website has been altered to remove the confusion.
To clarify the point it should be said "a compass must always be carried". In most cases it will not be used and in the mountains would only be necessary if one was starting navigation from a location such as the top of Townsend or the Watsons Crags ridge. In all other cases the GPS will show the direction of travel after a few metres travel and the data is updated every few seconds so that in practice someone using a GPS will rarely have need to consult a compass. If they lost their compass the GPS could give them the direction of travel so that any desired course could be followed.
A map and a compass are ESSENTIAL for backcountry travel and a GPS is useful. In some weather conditions or locations none of them will be used but in other conditions successful navigation depends on instinct, intuition, an awareness of the terrain and where one is, where one is going, where one may end up in error and careful use of a map and compass or GPS.
Some skiers set off on a day trip to climb to the top of a peak, get into cloud and insist on continuing. I think that they need a brain scan, why not ski in clear visibility or in a safe area?
A GPS is not infallible. One error that could occur, say if you were skiing along Watsons Crags ridge and switch on the GPS to record the track while you are moving. Later in cloud you use the GPS to retrace your track and follow it and ski over the cornice. Why? Because when first switched on, the GPS records a track with an accuracy of say 75 metres and may take a minute to achieve a 6 metre accuracy. If recording a track, make sure that the unit is working at best accuracy and insert a waypoint at the start before moving off. Secondly, if the GPS unit is operated in a battery saver mode it will only receive intermittent signals and will not give dependable tracking accuracy in some situations. The unit should be in normal mode to record waypoints and at any time when accuracy is essential. Better to waste batteries and save a life.
The September K&G article was an extract from the KCros website page on navigation and should be read in conjunction with the complete text. The page at www.kcros.org.au has been updated include reference to the new series topographic maps. Note that grid references from the old series maps are not applicable on the new series maps.
Back to Archive index