You could get software from strategic fishing systems link below
http://www.plantocatch.com/contourelite.html
This software will allow you to view a lake and explore it and select way points that you want to fish and up load those way points to many GPS devices and use the hand held GPS while your on the water. I use it as a plan of attack for a lake.
What is also really cool is you can view the lake bottom in 3D and explore the lake. I just wish you could select way points while viewing in 3D mode?
You can go to the link and see what lakes are featured in the software. They use Lakemaster lake data
Bob