Profiles of O//3 and other meteorological parameters of the atmospheric boundary layer were obtained at a location in the center of Athens. Surface measurements of O//3 were conducted in a number of other locations which included the shoreline and an island. The measurements confirmed well known models for the effect of sea breeze on photochemical pollutants and the diurnal variation of O//3 in the evolving atmospheric boundary layer and showed that pollutants released in the evening and early morning hours are advected offshore where they generate O//3 which in turn is advected back to the city by the sea breeze. They also showed that Athens pollutants are found in considerable concentrations in Aegina and outside the main basin to the north.