An accurate information on sea grass distribution is an essential prerequisite for managing sea grass resources in a coastal area. In this study, the four-flux model for the estimation of sea grass mapping is developed based on an inversion of reflectance estimation at sea bottom. This method considers parallel and radiative light transfers in the water and has capability for sea grass distribution and water depth estimation, together. The validity of the method was verified by the field surveys for sea grass meadows, bottom bathmetry and aerial photograph. The estimated sea grass coverage from the image shows nice agreement with the observed data.
