Abstract: The present invention is a device and method for stabilizing a chair on unstable ground. The device is particularly suited for chairs having horizontal or longitudinal leg support sections that contact the ground. The device comprises an elongated platform body having a longitudinal axis along its length and a horizontal axis along its width. The platform body has an upper surface, a ground contacting surface and a perimeter edge. The upper surface comprises at least one adapter positioned along the longitudinal axis for affixing the device to the horizontal or longitudinal leg support section of a chair. The increased surface area provided by the device reduces or eliminates instability when the chair is used on unstable surfaces such as sand, snow, gravel or grass.