Hello Erik:

You can toggle the usage of different mapsets on and off by going into the "Settings" menu of the GPS device and toggling the check marks beside the loaded maps there.

For example, on my Zumo 590, you select "Settings", then "Maps & Vehicle", then scroll down to "MyMaps", and you will see what is loaded there... you then select or deselect as you wish.

But, having said that, there are a few complexities and considerations that are not documented in the owner manual for the device.

1) Region of World: Garmin GPS devices are configured differently at the factory depending on what region of the world they are intended for. I am aware of both "Americas" (North America) and "Atlantic" (Europe & North Africa) configurations. There may also be Asian, Australia, and South America configurations, although I don't know about this for sure.

The region of world setup affects the built-in basemap that the device uses. This basemap is used at very wide zoom angles and also for depiction of topography. So if you have an Atlantic (European) unit and are using it in the Americas with an American mapset, you won't have the full functionality of a European unit. Some very wide views won't present well, and some topographical shading might not be present. The basemap is burned into memory of the unit at the factory and cannot be changed or toggled on or off.

2) Maps on internal memory vs. maps on chip: To the extent that it is possible, try to store your maps on the internal memory of the device, rather than on the little chip that can be inserted. This will result in slightly faster boot-up and slightly faster map redraw.

3) Turn off unused maps: Turn off - or don't load at all - maps for regions that you are not using. In other words, if you are in Europe and you have a chip with Morocco maps installed, either deselect the Morocco maps or just remove the chip. This will improve performance. On most devices, you can remove the chip and attach it to the inside of the battery door with Scotch tape - this ensures you don't lose the chip.

4) Route Planning: If you are doing route planning on BaseCamp and transferring the routes to your device, be very alert to note what map is being displayed on BaseCamp when you are creating the route, and be sure to have that map (and that map only) active on your GPS when you go to ride the route. Otherwise, the route will be recalculated by the device when you load it and will differ from the route you created.

5) Map Versions (of the same map): Because you are using BaseCamp to create routes, I strongly suggest that you delete from your computer any old or out of date versions of Garmin maps that you have downloaded. This will eliminate the risk that you have (for example) a 2021.1 version active on your computer and a 2021.2 version active on your device, which will result in route recalculation on your device when you load the route to ride it. You accomplish this deletion from the Control Panel of your computer (Programs & Services).

Michael