Port Stephens, an open youthful tide dominateddrowned valley estuary, is a large natural harbour of approximately 134 square kilometres (52 sq mi) located in the Hunter Region of New South Wales and is larger than Sydney Harbour. Port Stephens lies within the Port Stephens-Great Lakes Marine Park and is situated about 160 kilometres (99 mi) north-east of Sydney. The park was established to protect the wide variety of sea life that inhabit the port and nearby coastal areas of the Tasman Sea from just south of Forster to the northern end of Stockton Beach. The harbour lies wholly within the local government area of Port Stephens; although its northern shoreline forms the boundary between the Port Stephens and Mid-Coast local government areas. The port was named by Captain Cook when he passed on 11 May 1770, honouring Sir Philip Stephens, who was Secretary to the Admiralty. Stephens was a personal friend of Cook and had recommended him for command of the voyage. It seems Cook’s initial choice had actually been Point Keppel and Keppel Bay, but instead he used Keppel Bay later. Port Stephens is a popular tourism destination with a strong focus on aquatic activities such as whale and dolphin watching, fishing and recreational boating and swimming.
Port Stephens is formed through the confluence of the Myall and Karuah rivers, Tilligerry Creek, and the Tasman Sea of the South Pacific Ocean. The lower port has a predominantly marine ecology and the upper port an estuarine ecology. The area to the east of Port Stephens comprises the Tomago/Tomaree/Stockton sand beds. Port Stephens extends approximately 24 km (15 mi) inland from the Tasman Sea and at its widest point, between Tanilba Bay and Tahlee, it is 6.5 km (4 mi) across. The narrowest point is between Soldiers Point and Pindimar where the distance is only 1.1 km (0.7 mi). Between Nelson Bay and Tea Gardens, in the most well known section of the port, it is 3.8 km (2.4 mi) wide. The Karuah River drains into Port Stephens at its north-western corner. The Myall River (through the Myall Lakes) drains into the port on its northern shore, about 5.7 km (3.5 mi) from the mouth of the port. Twelve Mile Creek drains into the port’s south-western corner.
The southern shore of the port is divided into two distinct areas known as the Tomaree and Tilligerry peninsulas. These are separated by Tilligerry Creek, a watercourse covering approximately 7.7 km2 (3.0 sq mi), which drains the land in the low-lying areas of Salt Ash, Bobs Farm, Tanilba Bay and Mallabula. While the Tilligerry Peninsula is geographically closer to major centres such as Sydney and Newcastle, it lacks the urban development that has occurred on the much larger (25 km2 (10 sq mi) vs 115 km2 (44 sq mi) respectively) Tomaree peninsula. Although Lemon Tree Passage, on the Tilligerry Peninsula, and Soldiers Point, on the Tomaree Peninsula, are only 2.9 km (1.8 mi) from each other, physical separation of the suburbs by Port Stephens and Tilligerry Creek results in them being almost 40 km (25 mi) from each other by road. The town of Karuah, located at the north-western corner of the port near the mouth of the Karuah River, experiences similar geographical separation from the Tilligerry Peninsula. Despite being only 7.7 km (4.8 mi) from Tanilba Bay, the road distance between the two suburbs is 40 km (25 mi). The western shore and the western part of the northern shore of the port are largely undeveloped with the flora ranging from scrubland in the west to the large tracts of bushland which are present along most of the northern shore. Closer to the mouth of the port, at and near Winda Woppa, sandy beaches are prevalent. These extend from Jimmys Beach, near the mouth of the port, to the mouth of the Myall River, a distance of approximately 5.2 km (3.2 mi). Just outside the mouth of the port lie the two small insular nature reserves of Cabbage Tree Island and Boondelbah Island, both dedicated to the conservation of the threatened Gould’s petrel, and with no public access.
More than 85% of the population around Port Stephens resided in towns and suburbs that have developed on or near the southern shores of the port. More than 22,188 people live within 3 km (1.9 mi) of the port in the suburbs of Corlette, Lemon Tree Passage, Mallabula, Nelson Bay, Oyster Cove, Salamander Bay, Shoal Bay, Soldiers Point, Tanilba Bay and Taylors Beach. Another 5,343 people live in other suburbs on the Tomaree peninsula that are within 10 km (6 mi) of Port Stephens. These suburbs include Anna Bay, Boat Harbour, Bobs Farm, Fingal Bay, Fishermans Bay and One Mile. Most urban development to the south of Port Stephens has occurred on the Tomaree peninsula in the suburbs of Corlette, Nelson Bay, Salamander Bay, Shoal Bay and Soldiers Point. On the western shore is the suburb of Swan Bay, a small community of around 100 persons. The main industry in the area is oyster farming, however a small tourist resort is located near the mouth of Twelve Mile Creek. Karuah township, which has a population of 857, is at the north-western corner of the port, at the mouth of the Karuah River. East of the Karuah River, in the Mid-Coast Council local government area there are 3,584 people living in Bundabah, Carrington, Hawks Nest, North Arm Cove, Pindimar, Tahlee and Tea Gardens.