This is a device a client of mine has developed. He does a lot of lake fishing from boats, and has very good luck in catching nice fish. He has developed a trolling device that helps to do that. You put your rod and reel in the rod holder, and as the boat slowly plies the lake, the trolling device moves the rod back and forth, with pauses settable by the user. This back and forth movement , combined with the motion of the boat, causes the fishing lure to have an erratic, stop and go, slow and fast motion. The fish can't resist it!!
The inventor is in the process of licensing the invention, and if you want to manufacture or sell this device, contact me for the inventor's number.