If upon the hearing the offense is established, the judge of the district court must fine each of the offenders as is provided for in the section of this chapter which is violated or as otherwise provided by law and, if the fine is not paid, must commit him or them to jail and must also condemn the boat, vessel or craft, together with her tackle, apparel, furniture and appurtenances, forfeited to the state, and direct that it be sold and adjudge the cost of the proceeding before him to be paid by the accused. If he is not satisfied from the proof that the accusation is established, he must discharge the accused and release the boat, vessel or craft and other property seized.