Abstract: A convertible, collapsible shelter apparatus for use on land and in a body of water comprises a buoyant vehicle in combination with a shelter assembly. The buoyant vehicle has (a) an inflatable frame, (b) a flexible member whose perimeter is sealingly attached to the frame, and (c) anchors for holding a spaced plurality of pole members. The shelter assembly has (a) a plurality of struts which are removably held by the anchors and extend upwardly therefrom and across the floor, (b) a flexible cover supported by the struts and which extends to proximate the perimeter of floor and has an entrance for an occupant of the shelter; (c) an inflatable cushion which covers the frame and is removably retained against the floor by the frame, and (d) fasteners for holding a bottom portion of the cover proximate an edge of the cushion. When the cushion, the struts, and the cover are removed from the vehicle to form a tent, the fasteners are capable of maintaining the cover proximate the cushion.