# Adding Basemaps to GPS Units

There are a number of ways to add basemaps into Garmin units, but the most straight forward is using QGIS. 

The [GarminCustomMap ](https://plugins.qgis.org/plugins/GarminCustomMap/)plugin exports the current map canvas to a .kmz-file, which is compatible with Garmin\`s Custom Maps format for handheld GPS units. That way individual maps styled in QGIS can be used as background maps on the compatible Garmin GPS units.

{% hint style="info" %}
You would normally receive field maps from MAGIC in .pdf, .geotiff and .kmz (Garmin Custom Maps) formats.
{% endhint %}

### How to use GarminCustomMap

1. Add your map to your project.  **This .tif file should already be georeferenced** - if not, please contact MAGIC or use the Georeferencing tool (under the Raster drop-down).  
2. Change the projection to **WGS84**
3. Move the map to fit the map canvas entirely (see below)
4. Open the plugin: 
   1. Choose where to save the new file
   2. Set the zoom/scale - must be <8.9 for Garmin 78 devices, <20 for Montana devices
   3. Tick "Skip production of empty (entirely white) tiles

![Map in WGS84.  Note how it looks warped - that's because the map was originally made in a different projection.  ](/files/-MW4V6A-Cgjtu3wwYDlh)

This produces a high-quality .kmz that is compatible with your devices. &#x20;

### Adding data to a GPS

Adding data to a GPS is similar to adding data to any other USB device.  After you have connected your GPS to the PC you are using, just click and drag the .kmz file from where you have saved it to the relevant folder in the device. &#x20;

{% hint style="warning" %}
In the case of Custom Basemaps, Garmin units have a folder:

**(Garmin device drive) /Garmin/CustomMaps**
{% endhint %}

{% hint style="info" %}
Garmin devices use **"Spanner Mode"** to show up on a PC and access the data on it. &#x20;

Got to System Setup -> Interface, and select "Garmin Spanner." &#x20;

Then when you connect it to the PC you can choose **Mass Storage**
{% endhint %}


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