FarmerChris copper and dipsy divers are used to get your lure down to where the fish are and at the same time get back away from the boat. Put the coppers on boards and now you're away from the back and on the sides, making a bigger, wider spread with the theory being the fish are boat/cable shy. Some days the only strikes come on these lines. Depth of both depend on how much line is out, speed and current. Just some more tools in the tool box. As far as braid or wire, I run both but mostly wire.