An insulated cover for a pool includes a plurality of panels joined in edge to edge relation with one another to form a panel assembly for covering the surface of the pool. Each of the panels includes an upper and a lower sheet member joined together at their edges so as to form a flat surface around the perimeter of the panel and a pocket within the center of the panel. An insulating member is fitted within the pocket between the two sheet members. Panel tie members join the various panels together in edge to edge relation and a plurality of anchor tie members join the edges of the panel assembly to a plurality of anchors around the perimeter of the pool or lagoon.