People have already posted a lot of great ideas.
Here are a couple of more.
From the dock behind the Yacht Club (just next door to BCV's) there is a boat dock. From there you can take a boat to: Epcot, Boardwalk, and MGM Studios. Even thought it is faster to walk to Epcot and the Boardwalk, you might want to take the boats if your tired or want to try something different.
Also, you can walk from the BCV's to MGM Studios (just imagine taking a break from boats and busses to get somewhere). We have done this twice. It is a bit of a walk, maybe about 20 to 30 minutes or so, but it is a nice walk, and gets you away from the crowds for awhile.
The last item isn't specific to the BCV's, but since you leave from the Yacht Club dock, I will mention it. There is an "Illuminations Crusie". You can find many postings about it. It is a bit on the expensive side, but the boat holds 10 to 12 people, so you can split the cost with others. The Illuminations Crusie leaves from the Yacht Club Dock, drives around for a bit, then parks under the bridge, in Epcot between England and France, and then takes you back to the dock afterwards. The view of Illuminations is very good. We have done this once, and enjoyed it. However, it was a bit costly, and we probably won't do it again, or at least not for a couple years.
Thats about it. Most of all, relax and enjoy your stay,