An increase of more than 40% in both the mean and fluctuating parts of the electric field strength and air-earth current has been observed during the day-time development of the convective boundary layer under the influence of the sea breeze. This is attributed to the advection and turbulent organization of surf- and wave-generated space -charge. Fluctuations in the electric field strength have been subjected to variance spectral analysis in the range 0.001<f<0.05 Hz. Spectral estimates are found to be proportional to fx where x=-1.62¿0.19. This is compared with the -5/3 value applicable to the wind vectors, temperature, and humidity in the surface layer. An attenuation of short-period, horizontal charge -cloud structures is observed with the influx of sea air.