Warrior Tasks TC 3-25.26

Land Navigation

Map reading, grid coordinates, terrain features, and compass use.

Map Colors

  • Black: Man-made features (buildings, roads, boundaries)
  • Blue: Water (rivers, lakes, swamps)
  • Green: Vegetation (forests, orchards, vineyards)
  • Brown: Contour lines and relief features (elevation)
  • Red: Major roads, built-up areas, special features
  • Red-Brown: Combination of red and brown (used on red-light readable maps)

Terrain Features

There are 5 Major, 3 Minor, and 2 Supplementary terrain features:

  • Major (5):
  • Hill: An area of high ground; contour lines form concentric circles
  • Valley: A stretched-out groove in the land, usually formed by a stream
  • Ridge: A sloping line of high ground with varying elevations
  • Saddle: A dip or low point between two areas of higher ground
  • Depression: A low point in the ground, shown by closed contour lines with tick marks pointing inward
  • Minor (3):
  • Draw, Spur, Cliff
  • Supplementary (2):
  • Cut, Fill

Grid Coordinates

  • Grid coordinates identify a location on a map:
  • 4-digit: Identifies a 1000m x 1000m grid square
  • 6-digit: Identifies a 100m x 100m area
  • 8-digit: Identifies a 10m x 10m area
  • 10-digit: Identifies a 1m x 1m area

Remember: 'Read RIGHT and UP' — the first digits are the easting (left to right), the last digits are the northing (bottom to top).

Declination

  • The declination diagram on a map shows the angular difference between:
  • True North (North Pole)
  • Magnetic North (where your compass points)
  • Grid North (map grid lines)

The G-M angle (Grid-Magnetic angle) is used to convert between grid and magnetic azimuths.

  • Converting Grid to Magnetic:
  • East Declination: SUBTRACT the G-M angle ('East is least')
  • West Declination: ADD the G-M angle ('West is best')

Board Tips

Know the 5 major, 3 minor, and 2 supplementary terrain features cold. Know map colors. Be able to explain how to plot a 6-digit grid coordinate ('Read RIGHT and UP'). Remember the Grid-to-Magnetic conversion rule: East is least (subtract), West is best (add). For SOM/NCOM boards, you may need to demonstrate compass use and terrain association.