At a time when public attention is focused on the environment, while simultaneously society is increasing at an ever-accelerating rate its demand electrical power, the possibility of utilizing the power of the oceans by for pollution free tidal power generation is most attractive. Tidal power has been used to a limited extent over several centuries but only recently has any sig­ nificant effort been dedicated to realizing some of the vast potential. The first pilot project at La Rance has now been operating successfully for several years and the second experimental station using up-dated construc­ tion techniques has been in operation at Kislaya Guba since 1969. These projects have contributed valuable experience and establish the technical feasibility of this important source of electrical power, while providing guid­ ance in those areas requiring further development to realize economic viability. More than fifty sites can be readily identified around the world where tidal power schemes could realistically be developed. With improvements in technology, this number might well be extended by utilization of a large number of river estuaries. Such developments must be considered not only on the basis of the production of electrical power but also in respect of associated benefits. Considerable bodies of water would be partially confined, thereby improving recreational facilities as has already been experienced at La Rance.