I have never fished Fontana, but some fellows I know fish it for Walleye. They told me that the water is so super clear that you can drop a dime in 30 feet of water and tell if it's on heads or tails. They also said the fish are so spooky, due to the clear water, that they troll at least 200 feet of line out the back and troll at least 100 feet of line behind there planer boards and run the boards at least 80 feet out from the boat. They have never mentioned Crappie before being in Fontana. They're may be to many fish with teeth in there that would eat the Crappie.
Good luck.
Kellog