Ai Chi and Water Exercise for Parkinson's

I recently came across a reference to Ai Chi (Tai Chi in the water) and became interested in it's possible benefits for Parkinson's patients. I have not tried this exercise program yet, but wanted to pass along the link for the books and CDs that I found available at aquagear.com.  They are a swimming supply company online and have many books by Ruth Sova who has developed instruction materials (including CDs and DVDs) for Ai Chi. There is, also, a book available from aquagear called "Water Exercise for Parkinson's". I'm ordering some of this material and plan to help Don "get back in the water" and try some of the exercises with him.  I'll keep you posted on how this all works out.  If anyone has had experience with Ai Chi and Parkinson's I'd love to hear from you.