Abstract: A vertically adjustable pool platform, for use in a swimming pool, means to vertically raise and lower the platform, and means connecting the platform to the means to vertically raise and lower the platform, the pool platform being buoyant to float on the surface of the water, and be constantly urged to float to the surface of the water, when submerged under water at a predetermined level, and the platform permits vertical passage of water therethrough.

Abstract: A method and means of preventing heat convection in a solar pond is disclosed with the means comprising a liner element adapted to cover the sides and floor of a solar pond with the liner element having a bottom portion corresponding to the floor of the pond and side portions corresponding to the sides of the pond and a plurality of membrane elements extending between the sides of the liner element and sealably connected thereto so as to form a plurality of liquid layers with each said layer being fluidly sealed from the immediate adjacent layers and the membrane elements being of a transparent film material.

Abstract: An adjustable flooring structure for swimming pools is formed by a series of large, flat, panel-like modules interconnected to form a floor. The structure includes ballasting means formed by serially connected pipes in the modules which pipes can be filled with water or air to alter the buoyancy of the structure as desired. The structure is supported from the pool floor on adjustable legs and without the legs has a low overall height so that it can be settled to the bottom of the pool when not required for use.