(4)For the purposes of this Part of the Chapter, the tonnage shall—(a)mean the tonnage of a ship or inland vessel, as the case may be, indicated in the certificate referred to in sub-section (9); and(b)include the deemed tonnage, being the tonnage in respect of an arrangement of purchase of slots, slot charter and an arrangement of sharing of break-bulk vessel, computed in the manner, as may be prescribed.
