The physical properties of the air/sea interface may be significantly modified by adsorbed monomolecular films of surface-active materials. Damping of capilary waves, retardation of evaporation, inhibition of microconvectional cells, and modification of air-bubble properties are some of the microscale surface parameters affected by these monomolecular films. The concentration of airborne salt condensation nuclei produced from bubbled seawater is also altered by surface-chemical effects. These microscale effects can influence larger scale geophysical parameters, such as the transmission and reflection of light from the sea surface, the production of condensation nuclei by bursting bubbles, and the diminution of waves. While natural sea slicks may occasionally exist and alter sea-surface properties, artificial surface films, which are more durable and effective in modifying air-sea interactions, have been selected on the basis of a series of field and laboratory experiments. Optimum ocean performance was demonstrated by oleyl alcohol, a chemically unsaturated fatty alcohol which forms a rapidly spreading, coherent monomolecular film produces large capillary-wave-damping effects, and does not interact chemically with seawater.