Two concrete floating structures study projects representative of future developments in the field are described. The first is a power plant concept feasible in the near term. The second is a more futuristic, very large floating structure in the form of a floating airport, several orders of magnitude larger than any structures presently afloat. Both structures are within the state of the art in terms of design and construction, their size alone being the only "new frontier'. Special features and proposed construction procedures are described.