Look for your deeper holes with no or little current. In the fall when I lived in Missouri I'd paddle miles of river only fishing where I saw leafs on the surface, deeper water and brush. In many of the rivers I fished the water would only be maybe 6 foot deep and you would seldom find the Crappie shallower than that 6 foot mark. Any current at all and the Crappie weren't there. This allow you to eliminate 95% of the water. Good luck and keep after them!