Are you saying - take the newly updated card (from mapsource) out of the GPS, put it in the computer and transfer the maps from the previous card to it? I know when you use mapsource to transfer new data it wipes out the old, won't that happen in a micro sd card to micro sd card transfer? will the GPS read the old and new data?
Okay thank you for explaining the difference between a segment and a map I tried a google search and looked on the Garmin site but couldn't figure it out. This might not be the correct forum but does anyone know of any water contour map sources, other than the Garmin ones, for my GPS, theirs doesn't cover several of the lakes I fish?