The diffuse attenuation coefficient for down-welling irradiance $K_d({lambda})$, which is the propagation of down-welling irradiance at wavelength ${lambda}$ from surface to a depth (z) in the ocean, and underwater visibility are important optical parameters for ocean studies. There have been several studies on $K_d({lambda})$ and underwater visibility around the world, but only a few studies have focused on these properties in the Korean sea. Therefore, in the present study, we studied $K_d({lambda})$ and underwater visibility around the coastal area of the Yellow Sea, and developed $K_d({lambda})$ and underwater visibility algorithms for ocean color satellite sensor. For this research we conducted a field campaign around the Yellow Sea from $19{sim}22$ September, 2006 and there we obtained a set of ocean optical and environmental data. From these datasets the $K_d({lambda})$ and underwater visibility algorithms were empirically derived and compared with the existing NASA SeaWiFS $K_d({lambda})$ algorithm and NRL (Naval Research Laboratory) underwater visibility algorithm. Such comparisons over a turbid area showed small difference in the $K_d({lambda})$ algorithm and constants of our result for underwater visibility algorithm showed slightly higher values.