Notwithstanding anything contained in sections 37 and 38, the Central Government may, if in its opinion it is necessary in the public interest so to do, by general or special order, from time to time, permit certain specified vessels or classes of vessels to discharge or ship goods or certain specified goods or classes of goods, at such place in a port or within the port approaches, in such manner, during such period and subject to such payments to the Board and on such conditions as the Central Government may think fit.