(4)For the purposes of this Chapter, the tonnage shall mean the tonnage of a ship indicated in the certificate referred to in section 115-VX and includes the deemed tonnage computed in the prescribed manner"> (4) For the purposes of this Chapter, the tonnage shall mean the tonnage of a ship indicated in the certificate referred to in section 115-VX and includes the deemed tonnage computed in the prescribed manner.Explanation. - For the purposes of this sub-section, "deemed tonnage" shall be the tonnage in respect of an arrangement of purchase of slots, slot charter and an arrangement of sharing of break-bulk vessel.