Whoever, being the master of a ship,--
         (a) fails to comply with the provisions of section 40, or
         (b) without reasonable excuse, the burden of proving which shall lie on him, fails to deliver any postal article or mail bag or to comply with the directions of the officer in charge of the post office at a port of arrival, as required by section 41,
shall be punishable with fine which may extend to one thousand rupees.