overwrite base map?

[Diversions]

This is an awesome resource but a lot to soak up for a new user. My previous Garmin did not have the option to load maps so I want to learn as much as I can use utilize all the functions of my Colorado 300. The 300 has a vague basemap, is it possible to overwrite that map with a topo map, bluechart, or road map? In essence turning the Colorado 300 into a 400t, c, or i. I have the garmin 2008 nt street map on sd card and it is easy enough to switch back and forth but if I can avoid having another card laying around I would give it a try. Thanks for the web site.

[Diversions]

ok, that sounds good. I have downloaded the topo software which expanded into file "SEUSA"  and it works great. I can tell i will be spending some time trying to figure out how to overlay the new information, but it will be worth it. seusa is much more detailed and it corrects alot of the street number and road errors.

[Indrid Cold]

Glad it's working out. If you have any other questions feel free to post.