A model of ambient noise is described which permits one to estimate the density of whitecaps at the sea surface as well as the scaling as a function of wind speed of whitecap coverage and characteristic surface. This model relates the statistical properties of underwater sound (first and second moments) to whitecap distribution at the sea surface and to underwater sound propagation. The sound propagation model accounts for seabed reflections. Simulations show that seabed reflection effects can be great in shallow water, implying that the listening radii for hydrophone measurements, as defined by Farmer and Vagle (1988), can often be very large compared to hydrophone depth. ¿ American Geophysical Union 1993