Intense - When you do get the Navionics map cards, make sure you register them With Navionics and get the 1 year free weekly chart updates. Go here and click on "Freshest Data" and learn more about it.
http://www.navionics.com/LakeFeatures_HMPlatinum.asp
I have a HotMaps Premium East card and I was stunned at the additional detail I got for Old Hickory and Percy Priest when I signed up and updated my maps. You download Navionics World and go through the process and your card gets updated. Make sure you download the free PC App program that allows you to view the lake maps on your PC, its a great scouting tool.