I have the nuvi 265W. There is a specialized marine map that is compatible with Garmins, and I'd like to load it using Sendmap20 as per instructions. But the download for the map warns,
If you load this file into your Garmin GPS, it will
(A) Erase any maps already loaded by Mapsource or any other
program. After verifying that you are able to load 3ISLANDS,
you may reload other maps.
(B) It will cover and hide the base map in your GPS.
A) doesn't concern me, but B) does! If I load this map, how will I be able to get my base map back so I can use my Garmin on the road again?