UTM Mapping

• Universal Transverse Mercator (UTM) is a type of map projection where location can be given with varying numerical accuracy

• UTM maps are divided using the metric system. This system is ideal for ground operations on foot, since distances walked (meters) can easily be measured and plotted on the map.

• No two grids will have the same number.

• Reading gridded maps: Read Right, then Up

• The lines of a gridded map form small squares 1000m on each side called grid squares

• The East-West number represents the first half of the grid coordinate, and the North-South number is the other half.

• The least accurate grid reference is four digits: it represents the bottom left corner of a 1000m x 1000m square

Read Right, Then Up:The East-West coordinate of the yellow box is

05The North-South coordinate is 12The yellow box’s grid location is 05 12

Sample Map Grid

For Better Accuracy:

• Each 1000m x 1000m grid square can be divided into 100m smaller squares with an accuracy of 100m.

• One number is added to each half of the grid coordinate

• Always remember to begin your reading from the southwest (bottom left) corner of the grid

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6-Digit Accuracy: Add one number to each half of the grid coordinate to get an accuracy of 100m

Point 1: 054 126Point 2: 057 122Point 3: 050 120

8-Digit Accuracy

• On most maps, an 8-digit coordinate will be the most accurate point you can get.

• 8-digit coordinates provide an accuracy of 10m. To get an 8-digit coordinate, use a gridder or a mental estimate to add one more digit to each half of your six digit coordinate, remembering to measure right, then up.

Sample Iron Man ES Course

CoordinatesPoint 1: 8042 5544Point 2: 8000 5535Point 3: 7993 5627Point 4: 7895 5594Point 5: 7947 5562Point 6: 7942 5487Point 7: 7990 5458Point 8: 7963 5436Point 9: 7890 5463Point 10: 7834 5470Point 11: 7779 5511

SolutionsPoint 1: __A6___ Point 2:___H5___Point 3:__K3___ (ELT Bearing 195)Point 4:___L1___ (ELT Bearing 223)Point 5:__M7__Point 6:___A9___ Point 7:___H4___ (ELT Bearing 340)Point 8:__C6___Point 9:___D2__ (ELT Bearing 073)Point 10:__A9___Point 11:___B3__

Estimated ELT Location:___7974 5511________

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87

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