The paper considers the problem of dynamic positioning nonlinear model of a vessel under the multi-harmonic disturbances. The multipurpose control law makes it possible to tune the nonlinear observer, the feedback control, the dynamic corrector, and the estimator of external disturbances frequencies independently from each other. We achieve the economical ship control mode by tuning the dynamic filter to the primary external perturbation frequency. We apply a finite time approach to construct estimates of multi-harmonic external disturbance frequencies.