Swallow Fins- this fishie is a modern Take on a traditional design designed specifically to work in our surf here in N.E. FL. Low Rocker board through out with a slight single to double with 4 channels running off tail. These boards works best with the FCS Power Twins plus a nubster, but also works very well with the FCS Modern Keel. The deep channels add stability to the twin fin set up. Not your typical twin fin.