You can display multiple mapset on almost ANY GARMIN GPS (except maybe a cheap $100 unit).
The problem with most GPS (Nuvi and Zumo) is you need to rename the mapset “gmapsupp.img” or “gmapprom1.img”.
Only Marine and Hiking GPS’s, like Montana, Colorado, Oregon can accept any map name, so you could put “pig.img” in the \Garmin folder and it should work.
If you cannot figure out how to rename this additional map, you can try “fusing” 2 mapsets together using MAPSOURCE or MAPINSTALL (remember, BaseCamp cannot send maps to GPS units). By combining both into one mapset, you might get multiple map options on your GPS.
You can follow the “BASIC TRACK”, not a Route, because I did not provide a Route and your City Navigator map does not contain all the roads we will ride, hence no Route possible.
A detailed map is helpful and intersections in the middle of nowhere. If you have all of the possible 2 tracks, picking the correct trail is much easier. If you follow just a track, and come to an intersection (remember, you will not see an intersection on your GSP) you have to guess at which trail to take. You might pick correctly, but then again, you might find your self drifting away from the TRACK and at this point, you realize, you picked the wrong trail and must turn around and pick the ‘other trail’.
Custom Symbols can tell you of impending doom (Deep Sand). If you don’t like Deep Sand, Stop and notify the rider behind you that you are going to Detour and go around the HARD WAYPOINT. You MUST tell the rider where you are going to meet back up with the TRACK, so we don’t loose you. The only problem I see if you getting stuck OFF TRACK and then nobody will know where you are. PROBLEM. If you don’t have Cell Tower coverage, BIG PROBLEM.