I documented my "Shallow End" project in this thread:

http://www.poolforum.com/pf2/showthr...ht=shallow+end

It is the ONE thing that I have found which makes a 4 foot deep pool enjoyable for kids who like to do more than just float.
I now have this in a 15' x 30' x 54" AGP

Please ask away if you have any questions (but my access here is limited, so I may not be able to reply too quickly)