estuarine waters "estuarine waters" means the waters of a river extending from the mouth of the river- (a) up to the point upstream penetrated by sea water at neap tides; and (b) in the case of the State of Sarawak, up to the limits set by the Minister, with the concurrence of the State Authority, in regulations made under this Act; ACT 317 - FISHERIES ACT 1985 2. Interpretation.