Moving/Changing BaseCamp's Map Directory

Try JaVaWa's GMTK tool http://www.javawa.nl/gmtk_en.html

GMTK tool looks exactly like the program I need. I'll give it a go tonight and let you guys know. Thank you for pointing it out, SUSSAMB!

Sorted things out:

GMTK did what I tried to do by hand - create symbolic links (albeit packaged in a very nice GUI). Unfortunately BaseCamp did not pick up the maps. I came to the conclusion that this might be a sandbox issue since I am using the BaseCamp version downloaded from the Mac App store. After removing this version and downloading a version directly from Garmin things came together: I was able to move the maps to a different directory either by creating the symbolic links by hand or using GMTK tool. Problem solved.

I came to the conclusion that this might be a sandbox issue since I am using the BaseCamp version downloaded from the Mac App store.

Good to know, I never used the App Store version of BaseCamp. Something for the manual of GMTK...

While we are on the subject, JaVaWa GMTK did move my maps to desired directories, but left multiple additional files behind that were installed with the maps from original vendors (including, but not limited to GPX files, PDF, word docs, images, etc.) - I still had to manually check each directory and copy what JaVaWa GMTK had not to complete the process. Can JaVaWa GMTK please be modified to move all data from the map directories during this process?

GMTK only moves the map related files. The reason is that certain map vendors put more than one map in the same folder. Moving all the files in the folder when you move a map would break the other map(s). Also, I've seen maps where all files weren't put in the same folder.

Moving maps usually leaves the uninstaller file (that doesn't work anyway after moving a map with GMTK), and an image file with a logo (if present). A text file with the copyright notice (if present, and properly installed) is moved along with the map.
Other items like GPX, PDF files and Word documents shouldn't be there in the first place (who's going to find them there?), but I know some OSM map creators like to bundle a lot of other items with the map. Garmin doesn't do that AFAIK.

All of this isn't an issue with gmap type maps, only with the older registry maps. When moving gmap maps, the whole folder is moved.
IMHO registry maps are a pain in the ... :p (you don't know how much trouble I had to get GMTK handle all of them properly); I'm glad that Garmin switched over to gmap type maps...