OK I want to say Thanks.. That javawa tool is absolutely essential if using multiple mapsets with basecamp..
Turns a horrid awful piece of software thats pretty much unseable.. In to merely a poor piece of software.
Previously basecamp would only see my maps.. On the garmin device, while in USB mode.. But then cannot write to the device, until its connected in garmin mode and cannot 'import' the maps.. So your constantly rebooting the garmin, changing it from USB to garmin mode, losing your map, or unable to send it the data.. I have no idea who thougth this was a viable workflow but this is what the public stocks were invented for.
One issue I had with the app was that, due to not reading any manuals, I put the maps onto a thumb and told the app to make them visible.. They were not.. They needed to be 'exported to' the thumb which just put them in a garmin subfolder like they would be on the device.. Simple but I didnt see any obvious instruction that this was what needed to be done.
Now I can keep all my maps sets on a USB stick, and switch between them with basecamp, while also keeping my GPS in garmin comms mode, and send waypoints and tracks to it.. Thats almost user friendly.