The observed levels of high sea-state surface-related reverberation are modeled as scattering from plumes of microbubbles. The plume model is constrained as much as possible by existing microbubble data, particularly the average bubble content as a function of depth measured by Farmer and Vagle [J. Acoust. Soc. Am. 86, 1897-1908 (1989)]. The Chapman-Harris [J. Acoust. Soc. Am. 34, 1592-1597 (1962)] and Chapman-Scott [J. Acoust. Soc. Am. 36, 1735-1737 (1964)] experimental levels are fit with reasonable parameter choices. Frequency and grazing angle dependence are predicted by the model. Wind speed dependence is not addressed in this paper.