By iLaria Marengo
Learning about projections and coordinate systems, navigation techniques, compass and bearing, and the use a Global Positioning System (GPS) nowadays can be a bit funnier thanks to geocaching, a modern version of the traditional treasure hunt.
In brief, geocaching consists in getting a pair of coordinates, loading them into a GPS and using the device to navigate to the point where a small box, the geocache, has been hidden. The cache is a small waterproof box and generally contains a logbook and the treasure, which usually are tiny items that have a particular meaning for the person who placed them. The people who find the cache are free to take its objects (except the logbook) but they must leave something of similar value.
It was an unexpected but pleasant surprise to find out that in Tristan da Cunha, the remotest inhabited island in the world, a series of caches had been hidden by the local tourist office as part of a commemorative geotrail. The 200 anniversary of the British Garrison in Tristan da Cunha was celebrated with parties and various initiatives and setting up a geotrail was one of these.
The opportunity of being the first to do the geotrail was then seized and seen as the best way to engage the oldest students of Saint Mary’s School to have an open air geography lesson about projections, maps and the use of GPS for navigation and marking spatial objects. Thanks to Anne, the head teacher who authorised the half day out, and the help of Sarah, fisheries officer, the kids in class 5 were taken around the settlement to learn how to use a GPS, how to mark a waypoint, enter coordinates of a point and navigate to it in order to find it. The day before the “hunt”, the six pupils were asked to write on a small piece of paper why they enjoyed living in Tristan. The papers would have placed in each cache as treasure for the next geocachers.
A map of the settlement with a sketch of the geotrail, the coordinates of each cache and a description of the importance of each site in the context of the British garrison period was given to the kids for reference.
The kids of class 5 learned very quickly how to use the GPS in the two hours of cache hunting and navigation. The day before rained heavily, however the muddy and soaked fields did not spoil the day and the amusement of the kids. The hope is to have passed to the kids a new skill which they can well use in Tristan and in any job with conservation, fisheries and public work.
It would have been great to show the kids how to map the points in QGIS. However, there was not enough time to plan for a GIS lesson, which was instead given to some of their parents!