Before you can ever gaff a tuna you have to fool one into biting, and for many anglers the initial step will be building a spreader bar. When it comes to offshore trolling there are only two basic food groups: natural, and artificial. And one lure - the spreader bar - stands out as a staple. There are many different sizes and variations of spreader bars, not to mention different colors. But the charter fleet is partial to one in particular. Any spreader bar can catch fish, but if you construct the following spreader bar, you will be dragging exactly what a large portion of the professionals have behind the transom.