The transport and fallout of dust during the advance of offshore dust cloud over water surface is studied. Some important issues concerning this problem are re-examined, particularly the effect of water surface presence on the concentration field and deposition rates of dust. The analysis will show that an inner of surface layer may exist near the water surface, where surface retention or absorption processes are dominating and that large dust concentration gradients will be sustained there. A logarithmic concentration profile is shown to exist, extending from the surface roughness height throughout the surface layer thickness, which will be shown to be dependent upon the wind strength and the dust particles sedimentation velocity. The surface layer structure will not be dependent upon the particular profile assumed by the initial dust concentration at the land-sea boundary, and the analysis will show that the dust fallout rates due to both sedimentation and surface absorption effects combined can be significantly larger than those commonly obtained by considering sedimentation effects alone. The theory can be used in assessing both the magnitude and the extent of aeolian sediments contribution to marine environment which exist adjacent to large desert area.