Measurements of illuminance at sea level, directional luminous reflectances of ocean water and other surfaces, atmospheric beam transmittance, and path luminance for a day with an unobscured, low sun are presented. These data are applicable for visibility calculations for downward paths of sight.
Almerian R. Boileau and Jacqueline I. Gordon, "Atmospheric Properties and Reflectances of Ocean Water and Other Surfaces for a Low Sun," Appl. Opt. 5, 803-813 (1966)