### ES-UTM Gridding Tutorial

```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.
Sample Map Grid
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 East-West coordinate of the yellow box is 05
The North-South coordinate is 12
The yellow box’s grid location is 05 12
• The least accurate grid
reference is four digits: it
represents the bottom left
corner of a 1000m x 1000m
square
For Better Accuracy:
1
2
3
6-Digit Accuracy: Add one number to each half of
the grid coordinate to get an accuracy of 100m
Point 1: 054 126
Point 2: 057 122
Point 3: 050 120
• 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
southwest (bottom left)
corner of the grid
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
Coordinates
3
4
5
2
1
1
6
1
0
9
7
8
1
Point 1: 8042 5544
Point 2: 8000 5535
Point 3: 7993 5627
Point 4: 7895 5594
Point 5: 7947 5562
Point 6: 7942 5487
Point 7: 7990 5458
Point 8: 7963 5436
Point 9: 7890 5463
Point 10: 7834 5470
Point 11: 7779 5511
Solutions
Point 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:
```