Abstract: A solar heating apparatus is disclosed herein useful as a swimming pool cover whereby the sun's rays can penetrate the apparatus and heat the water therebeneath. The apparatus includes a plurality of individual and separate units of a predetermined geometry which cooperate with each other to cover a given body of water. Each unit includes an upper panel of transparent, plastic material and a bottom panel of opaque, plastic material. The panels are joined at peripheries to provide an integral unit and spacers or ribs are provided to maintain separation between the opposing panel surfaces so that a thermal compartment is defined therebetween. In one form, the bottom panel may be a continuous strip of plastic material shared in common with separate top panels.