Brisbane Water is a wave-dominated barrier estuary located in the Central Coast region, to the north of Sydney, New South Wales, Australia. Brisbane Water has its origin at the confluence of the Narara and Coorumbine Creeks, to the south–east of Gosford and travels for approximately 18 kilometres (11 mi) in a southerly direction to its mouth at Broken Bay, about 7 kilometres (4.3 mi) from the Tasman Sea, at Barrenjoey Head. A number of towns surround the shores of Brisbane Water, including Booker Bay, Davistown, Ettalong Beach, Gosford, Green Point, Kincumber, Phegans Bay, Saratoga, Wagstaffe, and Woy Woy. Contained within Brisbane Water is St Huberts Island, Rileys Island, and Pelican Island; and adjoining the estuary is Brisbane Water National Park to the west and Bouddi National Park to