I'm in a similar predicament, same tablet too.
From what I've learned so far Oruxmaps (on Google Play) can do this job, but you need to get the map img unlocked in order for it to work
Even without the Garmin maps, it is a pretty good piece of kit, with on and offline mapping (Google maps, OSM, etc) . I've been playing around with it for a few days and I may just have a go at putting a proprietory img on it to test the offline capabilities.
The only alternative to that is to get a netbook running windows 7 for the sole purpose of running Basecamp, which I'd rather not.