Scientific Anglers Sonar Stillwater Seamless Density S5/S7 Fly LineDOUBLE DENSITY SINKING LINES The SONAR Stillwater Seamless Density lines are a unique departure from the traditional graduated density lines of years past. With a variety of double density sinking rates and a smooth, seamless transition between each, the SONAR Stillwater Seamless Density lines provide straight line connections to subsurface flies, meaning you're in control of the fly every second it's in the water. Designed specifically for the