The Mueller phase matrices of sea water were measured at scattering angles of 20°, 30° … 130° for ocean water, coastal water, harbor water, and river water. The measurements were made with a modified Brice-Phoenix light-scattering photometer. The measured phase matrices exhibit strong forward scattering, and the polarization is comparable in form to that due to Rayleigh scatterers but reaches a maximum value in the range 40%–70%. The matrices are also strongly diagonal and approximate the theoretical Mie scattering matrices for spheres.
GEORGE F. BEARDSLEYJR., "Mueller Scattering Matrix of Sea Water," J. Opt. Soc. Am. 58, 52-56 (1968)