I have been looking since forever for a website that would show lake underwater elevations. I finally found it and thought I would share it.

http://www.navionics.com/en/webapp

The little speaker looking thing in the left will give lakes more detail. Its some product they sell called Sonar Charts, basically people record their fishfinder depth readings and locations, and then share them with the Navionics and everyone else.

Sorry if you all already knew about it.