The results of investigation of aerosol in the atmospheric layer adjacent to water above the Atlantic Ocean are presented. The measurements were made using a photocounter of particles and a nephelometer equipped with thermo- and hygroactuators of aerosol. The influence of the continent on formation of optical and microphysical properties of aerosol above the ocean is analyzed. A variation in proportion of submicron and medium-sized particles is shown to be followed with a law by a change of thermooptical parameters of aerosol. A good reproducibility of these parameters for marine aerosol is noted.