The use of the three-parameter model of the submarine light field for determining the absorption and trapping of radiant energy in nepheloid layers is revised and clarified. Predictions of the relative amount of energy trapping in a nepheloid layer are compared with the detailed energy budget of that layer. The predictions are confirmed by the radiant energy budget. This model cannot be used to estimate the scattered component of radiant energy flux in the submarine light field. However, with the proper light field measurements, the three-parameter model can be extended to a four-parameter version consisting of the scalar irradiance (Eo), downwelling vector irradiance (Ez), average cosine of the downwelling radiant flux (μd), and the average cosine of the upwelling radiant flux (μu). This extended model is mathematically equivalent to the Preisendorfer irradiance quartet model and can be applied in similar ways to study the scattered radiant flux. ¿American Geophysical Union 1987