I treat the reflectance of light from coastal ocean water in terms of diffused volume scattering phase function P(θ) derived from successive products of the normalized volume scattering function β(θ). My results show that the wavelength dependence for backscattering in a multiple scattering process is directly proportional to the angle-independent dimensionless source function b/a, which is the ratio of the total volume scattering coefficient b and the total volume absorption coefficient a. I use this result to produce a statistical formula for remote sensing reflectance (R_rs). The statistical formula shows good agreement with experimental data, and—unlike the standard oceanographic expressions for R_rs given in terms of b_b/(a + b_b), where b_b is the volume backscattering coefficient—the statistical relationship for R_rs accounts for the effects of photon turnaround and reduces to the expected asymptotic limits for diffuse reflectance when a → 0 but b_b remains finite and when b_b → 0 but a and b remain finite.