Optical properties of the atmosphere over the ocean are essentially different from the optical properties of the atmosphere over the land. For a cloudless atmosphere this difference is determined by the mechanisms of aerosol formation. For cloudy atmospheres this difference results from different mechanisms of convection. Convection over the sea is essentially weaker than over the land and the cumuli-form of clouds over the sea is essentially thinner. We must take into account the differences between optical properties for the atmosphere over the ocean and over the land for the purposes of remote sensing, LIDAR investigations, and in calculations of the radiative energy transfer between ocean and atmosphere. Taking this into account, it becomes apparent that we must correct all preceding atlases and maps that do not reflect this difference. It is also important for engineers who design optical instruments for use in the atmosphere over the oceans to consider the implications of this difference.