Abstract: A frisbee balanced to spin about a central axis has a central portion with a top surface and an opposing bottom surface. The central portion terminates peripherally with a circular rim having a sinusoidal curvature. The central portion conforms to the sinusoidal curvature of the rim forming radial variations of peaks and valleys. Plural sinusoidal cycles of radially directed, convex peaks impart thrust enabling it to float in a chosen direction when thrown and to rotate about its central axis developing lift due to air passing over the generally domed top surface.