A structure can be installed in and removed from a body of water in a seasonal fashion. The structure has a lower level that includes a boat lift and may include an upper level that provides an entertainment area. The structure carries a buoyancy system for selectively floating the structure on the body of water or sinking the structure in the water. A substantially enclosed boathouse may form the structure when the structure has only a lower level. The boathouse is seperable into sections each of which could be separately rolled over the ground by wheels attached to each section. This reduces the usual operational width of the boathouse into the smaller towed widths of the individual sections to ease the task of transporting the boathouse over the ground.