I saw a video from one of the experts. If I remember correctly, he said that you need to keep the lures right next to the bottom. So, he used a line counter reel. He had it figured out so he could release line, or bring it in to put the lures at certain depths. After that, he just kept a sharp eye on the depth sounder. He said he spent his days adjusting line in and out to follow the contour of the bottom. Trolling is entirely different than bait fishing.
With bait, you pay your money, take your grass shrimp and fish in areas that have fish around.
I highly recommend talking to the old timers at some of the better bait/tackle shops. A trip or two with an experienced charter is invaluable. You'll be money and time ahead.