Abstract
Within the last decade there has been a great increase in the sophistication of ideas on wave generation, but the more complex observational data required to check these theoretical ideas are still lacking. Such data as do exist seem to support, at least qualitatively, the Phillips idea of the nature of the initial wave generation mechanism, but indications are that the Miles mechanism of wave generation at later stages is inadequate to explain the observed increase of wave energy. New ideas involving the effect of the turbulence in the air, and of different flow configurations from that proposed by Miles, are being proposed. The available observations are still inadequate to test these ideas. Of particular importance to the theory are measurements in the air below the level of the wave creasts.