Commencing from the mouth of Sungai Buntal at position Latitude 01° 41' 46"N, Longitude 110° 22' II"E, then following a line across to a position Latitude 01° 41' 30"N, Longitude 110° 22' 28"E proceeding upstream to Sungai Penambat and Loba Selasang then to Sungai Santubong.