The limits of the Port of Kunak shall be "a line drawn from the point (headland) on the mainland south of Wise Hill to the most easterly point of Pulau Sakar, thence in south-south-east direction to the most easterly point of Pulau Bohihan, and thence in a south-south-west direction to the peak of Mt. Cook at a point where the said line intersects the coastline, including rivers entering the same for a distance of 600 feet inland from the mouth of the river".