Spreader Bars are trolling jigs meant to catch big game pelagic species of fish. They create a lot of splash and commotion on the water to lure the fish in where they see a school of squid behind the splashing. The starboard side directional bar has a fin build onto the bottom of the bird that acts as a rudder. It will push the bar out of the wake on the starboard side of your boat eliminating the need for outriggers! Every fishery is different, but in California it works best from 75-100 yards behind the boat. Trolling speed can range from 4-8 kn.