BTW when I find an active crappie bite when trolling, I stop trolling and attempt backtracking; so I can hover over the bite spot. Alone I will then vertically jig, setting aside the spinner, if I am using one. More than one in the boat and if we can all jig up fish, the better. Other wise at least one of us will be casting to better pin point the school. For me trolling is to find the fish, then you drop candy bits right in their faces to fill the bag. I cannot think of any better tool to hold position in a hover than having spot lock on your electric.
Troll to find - hover to harvest.