a reflective propeller safety cover comprising a bag having a flat bottom wall and a side wall peripherally coupled thereto and extended therefrom to define a hollow interior sized for holding a propeller of an motor boat and a mouth for allowing access to the interior for receiving a propeller ; an adjustable coupling mechanism coupled to the bag for adjustably opening and closing the mouth ; and a reflector mechanism coupled to the bottom wall of the bag for providing a visual indication when light is shined thereupon .