Alvey's Downrigger can add a new dimension to trolling by getting the bait or lure down to the fish.
The method is a weight with a line release clip lowered by wire cable. The wire is attached to the clip with
about 10 to 20m of line to whatever you are trolling. The weight is then dropped to the required depth.
Use your fishfinder in conjunction with the downrigger, to pre-determine depths and adjust the drop accordingly. When you have a hook up, the line releases from the clip, and you can play the fish as normal.