Abstract: An inflatable body including first and second fluid impervious major panels, each having an outer surface, an inner surface and a perimeter, and further including a fluid impervious intermediate panel having a first surface, a second surface and a perimeter. A first perimeter portion of the intermediate panel is joined to the inner surface of the first major panel from one perimeter portion thereof to a generally opposed perimeter portion thereof, and a second perimeter portion of the intermediate panel, which is generally opposed to the first perimeter portion, is joined to the inner surface of the second major panel from one perimeter portion thereof to a generally opposed perimeter portion thereof. The first and second major panel perimeters are joined to each other, defining a primary enclosure having first and second chambers separated by the intermediate panel, and at least one sealable orifice in fluid communication with the environment and at least one chamber.