Abstract: Disclosed is an apparatus for protecting a swimming pool against damage due to forces created as water in the pool freezes and expands. The apparatus includes a hull that floats on the surface of the water and compresses as the water freezes and expands. A pair of straps attach the hull to a pair of bean bags to keep the float in a selected position near the side of the pool. The hull has a pair of side members and a pair of end members, forming a watertight hull. The side members are connected together along a common edge to form a V-shaped cross section. A plurality of weights are located in a semicircular slot along the common edge to keep the common edge downward in the water.