The essence of navigation is knowing where you are (A), where you’re going (B) and being able to select the optimal route from A to B. This process relies on the navigator being able to interpret the colours, shadings, symbols, scales and contour lines on the map, make assumptions about the terrain on the map from observations in the field and by correlating their 2D map with the 3D environment.
While speaking to Seagate’s Nathan Fa’ave – an accomplished and experienced athlete and navigator – at the 2004 Subaru Primal Quest, he mentioned a number of interesting points about the difficulty of navigation in the United States. Most of his observations are applicable to other events held outside our own borders.
- There are a dozen, if not more, map makers in the US. As such, from one region to the next, the maps are inconsistent. The maps they were using in this race differed to those they had last year and are substantially different to their New Zealand maps, which are standardised throughout the country (South Africa is the same). Map-makers have the freedom to use their own colours and symbols to represent topographic features and these do differ considerably.
- US maps are drawn to an imperial scale. For metric nations trying to convert from inches to miles and then converting to centimeters and kilometers is exceedingly difficult. Most non-US racers would have grown up in a world void of imperial measurements. Purchase an imperial rule on arrival and remember too that the scale on your compass’ base-plate will be metric.
- Many US maps are custom-made do not have side-panel legends to explain shadings and symbols. Nathan mentioned in particular the difficulty in interpreting road-types. This is important when the event’s ‘Rules of Travel’ restrict the competitors from racing on specific road types i.e. tarred or main roads. If you know the symbolic representation of the roads you can avoid those restricted and consider those allowed just by looking at the map. But, if you don’t know the colours and symbols used and are unable to interpret the type of road because of the absence of a legend, your route-selection task is made more difficult. You could end up avoiding a road because you think it is tarred, where in fact it may be a permissable dirt or primary road.
- There are many map versions available of the same area, each having information omitted in the other. Nathan mentioned that last year, especially on a particular mountain biking section, Nike ACG-Balance Bar had raced with three different maps of the same area and had three of their team navigating off them at the same time. Seagate had experienced difficulty in this area, losing precious ground to Nike ACG-Balance Bar. Learning from past experience, this year Seagate sent their support crew out to scout for additional maps so that they too would benefit from the little pieces of extra information to complement their race maps.
- Compasses – The vertical intensity and direction of earth’s magnetic field, the inclination, influences the horizontal plane of a compass needle according to the latitude where it is used. Due to the inclination, compasses are balanced for defined global zones to ensure that the needle’s movement is unhindered and that it lies horitontal when the compass is held horitontally. As such, your compass, which is balanced for South Africa (and some other Southern Hemisphere countries – check with the manufacturer) is not suitable for use in countries which fall under different zones.
- Map projections – Although geometrical coordinates (longitude and latitude) are well-known, other grid systems do exist like the Universal Transverse Mercator (UTM) and XY coordinate system. A grid projection is something like a ‘spiderweb’ thrown over the world, such that a precise location can be determined and related. As the coordinate grid is tied to the map through the origin and the origin of the coordinate system is placed near the center of the area of interest on the map, various regions have their own projections and grid systems i.e. British Ordnance Survey (UK) and the Universal Polar Stereographic (specific to the polar regions).
Solid navigation is paramount to success. As such it is wise to consider unfamiliar map types, scales, symbols, colours, contours and even map grid projections (UTM, Longitude & Latitude, British Ordnance Survey etc) when preparing for a race on foreign soil.
Nathan finds the US maps to be the most difficult in the world because of inconsistencies throughout the country. “Racing against American teams in the US and on US maps is hard”, he remarked. “I’d rather race against them in any other country.