an arrangement is disclosed which secures the sail to the mast of a sailing craft to achieve an aerodynamic profile about the mast while allowing curvature in the mast for optimum sail profile . the arrangement includes an outer profile sleeve of flexible material extending from a line of securement to the rear of the luff of the sail forwardly around the mast . the profile sleeve receives one or more semi - rigid , flexible profile members comprised of lightweight plastic sections configured to be tightly fit therein , stretching the profile sleeve into a high efficiency wing shape surrounding the mast . the wing shape includes a leading parabolic surface and curved sides smoothly transitioning into the main sail area to create a lift airfoil with the sail angled either to port or starboard .