57. Notwithstanding anything contained in section 55 or section 56 and subject to rules, the appropriate officer may grant a port-clearance in respect of a vessel or permission for departure in respect of any other conveyance, if the agent furnishes such security as such officer deems sufficient for duly delivering within ten days from the date of such grant, the export manifest and other documents specified in section 53 or section 54, as the case may be.