Tying the Snell Knot. The snell knot was invented long ago when it was the only way to attach the fishing line to an eye-less hook, but many anglers still use it today. One benefit of the snell knot is that it aligns the fishing line or leader with the hook shank, resulting in a straight, solid set. Snelled hooks are often used when fishing natural baits for species such as striped bass and flounder, and fly anglers have long used the snell knot to attach tarpon streamers to heavy leaders.