"What It Is: The popularity of wire-line fishing has come and gone a few times. In the early days, anglers used single-strand wire, which was capable of creating the backlash to end all backlashes. Nowadays, multi-strand wire or copper is the preferred choice. It's easier to handle, and its thin diameter allows anglers to fish greater depths with smaller lures.
How It Works: While many veteran anglers claim it's the wire line's harmonic hum that helps attract fish, others believe it is simply the line's inherent ability to place lures in precisely the same spot on each trolling pass. Wire cuts through thermocline water-density changes far better than either leadcore line or inline weights. Wire line can be spooled to completely fill a reel or segmented in sections as with leadcore.