The radiation restoring coefficients are calculated by equation (7) for the motions and equations (36)-(39) for the loads. These equations include memory functions, frequency dependent added mass terms and infinite frequency added mass terms, and theoretically the result should be the same for any frequency considered. However due to numerical errors, the representation of the restoring coefficients as function of the frequency results in slightly scattered results. The solution found was to consider the mean value of the scattered results.