9781422287859

Navigating with a Map and a Compass 13

Contour lines The differing height of the land is represented on a map by imaginary slices at vertical intervals, called contour lines. By studying these contour lines, elite forces personnel can build up a mental picture of the rise and fall of the land. Starting at sea level, each contour line represents a height above sea level. Contour lines are usually printed in brown, with every fifth contour being drawn in a heavier line. These heavier lines are called index contours, and somewhere along each one, the line will be broken and its height given. The contour lines between index contours are called intermediate contours.

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A map grid, the basic starting point of all map references. Grid references follow the rule “along the corridor and up the stairs.”