Port-due not to be chargeable in certain cases

No port-due shall be chargeable in respect of- (a) Any pleasure-yacht, or (b) Any vessel which. Having left any port., is compelled to re-enter it by stress of whether or in consequence of having sustained any damage, or (c) Any vessel which, having entered [any port fin the territories which, immediately before the 1st November, 1956, were comprised in the States of Madras and Andhra] or the Port of