If you look at the screen shot of the one for Milford lake I posted the map on the left split screen is a raster Map. The one on the right is a vector map and this is the one you are use to seeing on your GPS chart plotter. This is something new the raster map to be able to view it on your plotter. The raster map is the old map before the lake was built and flooded . Out in Western Kansas I have aerial photos that show the lake when they were way down like Cedar Bluff was down 50 feet when this aerial Photo was taken. These aerial photos are in the raster format same as the old maps you see before the lake was flooded. just remember you can only view the raster maps on the HDS units only. The elite 7 HDI can only see the Vector maps like you normal get. They may change this to include the Elite 7 I don't know. I am doing some testing now as I have an Elite 7 HDI in my office and I will post the results on what I find tomorrow. I am real busy today I have several orders for dealers and customers to send out. If you have anymore questions please let me know I will answer as time permits. I posted this because someone in the forum ask to explain the difference between raster and vector maps. When I post these screen shots just look at the screen and you will see the coordinates on the screen and this will tell you where the lake is located.