My gift to you, A Google Earth file.
Thanks to Redge who lived dangerously and after 2 fire extinguishers used on his pc, found the file to actually work.
Thanks to Gomer Snerd who unknowingly submitted his phone mapping pic for me to mess with.
The 2 lakes are Lake Nimrod, and Lake Charles. Nimrod has 2 overlays and is mainly the deep end. Lake Charles is pretty well the whole thing. I will leave the file up a short time, but will pull it down by tomorrow night since I don't have adequate bandwidth on the server. If you will PM me, I can tell you how to tweak these overlays some to make them more beneficial to you. I have checked the accuracy and they are pretty darn close.
http://home.centurytel.net/rcurt/nimrod311.kmz