Attached Link: http://sites.google.com/a/cgspeed.com/cgspeed/motion-capture/cmu-bvh-conversion

Found some. In the 'BVH directories 113-128' zip are about 18 files for swimming. The only problem is it's a 94mb zip! If you click on the full motions list it will tell you what motions are included. Scroll down to Subject #125 and #126.  I don't know how well they will work on V4 though, but I'm downloading them and will try them out.