How to Use a GPS with Map and Compass, by Kevin Outdoors on YouTube. 13 min 13 s.
- Video length
- 13 min 13 s
- Time to do it
- 20 minutes
- Difficulty
- Medium
- Steps
- 8
What you need
Steps
Check the datum printed in your map margin, such as NAD27 or WGS84, then set the same datum in your GPS menu. A mismatch can put your position hundreds of metres off.
Change the GPS position format to UTM so it shows a grid reference like 10U 0543210 5432100. That matches the grid lines printed on your topo map.
Stand outside with a clear view of the sky, switch the GPS on and wait for it to lock onto satellites. Note the easting and northing it shows.
On the map, use the first digits of the easting and northing to find the right grid square. Use the remaining digits with a romer scale to pin the exact spot.
Mark that point with a pencil and label it, so you can see at a glance where you are on paper.
To head for a target, plot it on the map first. Lay the compass edge from your position to the target and turn the bezel until the orienting lines match the map grid, then read the bearing.
Adjust that bearing for the magnetic declination shown in the map margin, or set the GPS to show magnetic north, so compass and GPS agree.
Walk on the bearing and check your distance by pacing or with the GPS track. Stop every so often, take a fresh grid reference and plot it to confirm you are on line.
Tips and common mistakes
Keep the GPS in a warm inner pocket in cold weather, since cold drains batteries fast.
Calibrate the GPS compass well away from metal, cars and power lines.
Practise the datum and UTM setup at home before you rely on it in the field.
Carry the paper map and compass as your backup even when the GPS is working.
Questions
Which datum should I set in my GPS?
Use the datum printed in the margin of your paper map, often NAD27 on older USGS maps or WGS84 on newer ones. If the two do not match, your plotted position will be wrong.
Why does my GPS show a different format than my map?
The GPS may be set to latitude and longitude instead of UTM. Change the position format to UTM in the settings menu so the numbers line up with the map grid.
Do I still need a compass if I have a GPS?
Yes. A baseplate compass works without batteries and lets you take and follow bearings straight from the map, which is quicker than scrolling through GPS screens.
This guide was drafted from the video's details and general task knowledge. It has not been checked against the full video. Check the video and relevant product instructions before following a procedure. Report a correction.
