Abstract: A generally hemispherical dome designed to cover a hot tub comprises a pair of successively smaller spherical shells, generally quadrantal in configuration, which are pivotally connected to a pin member vertically disposed through the superimposed apexes of the respective shells. A deck surrounding the perimeter of the hot tub provides basal support to the shells as well as a bearing surface for roller wheels attached along the base of the smaller shell. Upon affixation of the larger shell to the deck the smaller shell is rotated about the pin member through a range of superjacent positions relative to the fixed shell. A plurality of arcuate ribs form the framework of each shell and extend from the respective base towards the apex thereof for connection to a circular rim member. Brace members within the rim are rotatable about the pin member extending therethrough to provide rotation to the smaller shell.