Map Reading and Navigation
Map reading and navigation tests grid references, scale, relief, bearings and compass work. The exam wants orderly procedure, not guesswork.
Grid references
Read eastings before northings. A six-figure reference gives a 100-metre square: the first three digits are the easting, the next three the northing. For 234567, go to easting line 23, add 0.4 of the square; go to northing line 56, add 0.7.
Scale and relief
Scale tells you ground distance. Contours show height; the interval is the vertical distance between them. Close contours mean steep ground; a V pointing uphill marks a spur or valley. Use conventional signs for roads, rivers, buildings and boundaries.
Bearings
A bearing is measured clockwise from north. Convert grid to magnetic bearing by applying magnetic variation: add or subtract as the map states. A back bearing differs by 180 degrees.
Worked example
A bearing of 045 degrees has a back bearing of 225 degrees. If variation is 2 degrees east and the map says add, the magnetic bearing is 047 degrees. The reasoning is to follow the map's stated direction of variation.
Traps
Reversing eastings and northings, counting from the wrong grid line, adding variation when it should be subtracted, and confusing grid north with magnetic north. Always estimate the point within the square.