The rotating helical skimmer assembly is designed to remove all grease, scum, and other floating material from the water surface, including light, slow-moving scum that will not readily float to traditional scum troughs. As the helical skimmer continually revolves 360 degrees, its rubber wiper blades lift the surface scum up a curved steel or concrete beach and deposit the de-watered waste into a stationary U-shaped trough.