Customs exemption for imported crew stores permits duty waiver when prescribed clearance and payment conditions are met. Exemption from customs duty is granted for imported stores from bonded stocks intended to be supplied free to crew of a Coast Guard ship, exempting them from the whole of the customs duty in the First Schedule and from the additional customs duty under section 3, subject to conditions: presentation of a prescribed shipping bill; payment of export duties, penalties, rent, interest and other charges; clearance order by the proper officer for taking on board; and following the Collector of Customs' prescribed procedure.