Drag and mass coefficients corresponding to Stokes' fifth - order theory have been determined from previously published wave and wave - force data. Comparisons between statistical distributions for fifth-order and corresponding first order coefficients have been made for varying wave steepnesses. For other existing wave data, from which the fifth order drag coefficients could not be determined , the statistical distributions of first-order coefficients have been investigated varying wave steepnesses. Statistically based fifth- order and first-order coefficient design values for varying Reynolds numbers are presented. Statistically based fifth and first - order mass coefficient design values are suggested . Comparisons between drag-coefficient distributions . and corresponding mass-coefficient distributions seem to provide some insight into the reasons for the scatter on the coefficients.