look at the Pro Troll black box. It is available from Outdoor Emporium in Seattle or Cabelas on line (Outdoor had some pretty good sales last year durring the outdoor and boat shows). As far as how they work, well you still have to know how to fish, but I also know that commecial and many charter guys won't fish without them. I first learned about fishing with them on a charter out of Tofino on Vancouver Island. After talking with the skipper for awhile I was convinced and he certainly was a proponent of the system. He was a commercial troller before starting to run charters and he said his experience was that the box definately helped, especially when the fishing was alittle slow. He was also pretty protective of his settings. I guess he was like most of us, helpful to a point!!