The range of applicability of present nuclear plant concepts has been assessed in relation to future nuclear plant siting needs. Future electrical generating requirements indicate a major potential need for offshore stations near the populous coastal states, and a survey has been made of the availability and characteristics of offshore sites. Consideration of population proximity, aesthetics, and water-depth requirements indicates that most of the East Coast has an adequate number of potential sites for near-term plants. However, careful planning and the deployment of large multiunit stations may be required for effective long-term use of the limited siting resource. On the West Coast, the large population and the relatively deep water of the California region contribute to the scarcity of shallow water sites suitable far breakwater-protected offshore reactor plants, and deep-water plants may have to be developed far the area. This will require resolution of several fundamental issues, including those of mooring reliability and platform sinking. Deep-water reactor platforms must be protected from ship collision, and a promising ship-arresting system utilizing cables and drag anchors has been conceived.