This paper presents a spectral wave prediction model, based on the radiative transfer equation, in which a personal computer can be utilized in the numerical computation. For the purpose of saving processing time and capacity of memory, the model is formulated as a decoupled propagation model for deep water waves, which traces propagation and growth or decay of each component wave separately. A method estimating directional spectra at a fixed location through the computation of each component wave along a straight wave ray reaching the location is adopted in the numerical integration of the equation. Hindcasting for wave data observed at several locations around the Japanese coast during many typhoons in recent years is attempted and the applicability is confirmed from the comparison between the hindcasted and observed results for significant wave height and frequency spectrum.