We consider the variability of spectra in case 2 waters with different scattering and absorption coefficients in order to examine the limits on the validity of RSR equals C bbt(lambda )/at(lambda ). The spectral scattering coefficient is shown to be strongly correlated with sediment cross sectional area. In high scattering environments the remote sensing reflectance can be linearly related to the particle cross sectional area. RSR spectra show a decrease with the absorption by dissolved organic matter (DOM) for (lambda) < 600 nm. However, at extremely high scattering levels, absorption by DOM and even pure water become less important in this region. THe transition from case 2 to case 1 waters appears to occur when the scattering to absorption ratio is less than 0.6. In situ ac9 and RSR data were collected in the northern coastal Gulf of Mexico and off North Carolina. The RSR spectra are shown to be relate to the in situ absorption and scattering coefficients, and the cross sectional area of the particles. We explore methods of characterizing waters based on the dimensionless ratio of the scattering and absorption coefficients.