What are common mistakes when using contour matching?

Misinterpreting Terrain Features

When using contour matching, it’s essential to accurately identify and interpret terrain features, such as ridges, valleys, and slopes. Misinterpreting these features can lead to errors in navigation. For example, a false crest can be mistaken for a real one, resulting in a wrong turn. To avoid this, study the map carefully, and look for multiple features that confirm the existence of a particular terrain feature.

Failing to Match Features Correctly

Matching features correctly is crucial when using contour matching. Failing to do so can result in significant errors in navigation. To ensure accurate matching, use multiple features and pay attention to the map scale. For example, if the map scale is 1:24,000, use at least three features to match, such as a river, a ridge, and a valley. This will increase the accuracy of the match.

Accounting for Map Scale and Legend

The map scale and legend are critical components of contour matching. Failing to account for these can lead to errors in navigation. For example, a map with a small scale (e.g., 1:100,000) may not show sufficient detail to accurately match features. Conversely, a map with a large scale (e.g., 1:5,000) may show too much detail, making it difficult to identify the correct features. Always check the legend to understand the symbols and colors used on the map.