Abstract: A buoyant cover has a planar body, the body having a first buoyant insulating layer, a second tensile layer overlaying the first buoyant insulating layer, the planar body having a periphery configured based on the tank perimeter to provide a limited gap with the tank perimeter, and the body defining a plurality of peripheral holes positioned about the periphery and proximate the periphery. The second tensile layer may be wrapped about an edge of the first buoyant insulating layer. There may be an underlying portion of the second tensile layer near the periphery. A peripheral seam may be sewn through the underlying portion and the first buoyant insulating layer. The peripheral holes may penetrate the underlying portion. There may be grommets defining the peripheral holes. The planar body may have a circular periphery.