Tuning in to the mind of the mapper.

So there you are, waiting for your start time in a forest that is new to you, possibly with a new or an ageing map, just raring to get into your run when you can use all your textbook orienteering skills to notch up a fast time. What you need to focus on is using fully the information on the map to lead you into the controls without mishap - but is it really so cut and dried? Many of us set out on runs with the assumptions made that the map provided is accurate and that we can interpret it fully right from the start - after all, our navigational errors are normally the cause of lost time. But some of those errors may well come from the above assumptions: an experienced orienteer might not be so trusting, particularly early on in a run. A list of possible problem areas is given below - all have cost me significant time (> 15 minutes) in events.

Ditches - an area criss-crossed with ditches may just have the larger (deeper or wider?) ones mapped. Remember this on entering such an area, as the ditches you count off might not all be on the map.

Clearings - the mapper may depict a clearing as an area without trees, one with less dense trees or one with much smaller trees in it. Also if the map was drawn some time ago trees may have grown up.

Vegetation change - get a feel for what the mapper sees as a vegetation change before you consider navigating solely from one. Certainly do not use one as an attack point for your first control.

Crags & boulders - one mapper’s crag can be another’s rocky outcrop that is not worth marking on the map. Generally the mapper will omit crags & boulders under certain heights but you do not know the heights when you start (although control descriptions can help define it). The heights will vary from area to area.

Marshes - Marsh sizes can vary significantly depending upon the weather in the weeks leading up to the event, but the typical size should be marked on the map. Also remember that streams can run dry in dry conditions while in a downpour there might be other, unmapped streams present.

Path/ride ends - the path or ride would have ended where marked on the map at the time of mapping but that is no guarantee that it still ends where marked, particularly on older maps.

Paths - number & use - particularly on older maps the number of paths in an area may have changed since the map was drawn or the usage may have varied. What is marked as a small path may be rather more than that once a few forestry vehicles have been along it.

So, having spread possible gloom and despondency with the above warnings, what is to be done during this exemplary run of yours. Firstly you should develop a feel for the relationship between what is on the ground and what appears on the map as your run progresses: so if you are passing by a boulder or crag marked on the map take a look at it and see what size it is - do the same with a clearing. Secondly, be aware of these pitfalls, particularly early on; take your time and rely on those elements in a map and your technique in which you have confidence - contours, big line features, path junctions, compass bearings and pacing. Also choose catching features that are very, very definite early on.