Gulf of Saint Vincent is a large inlet of water on the southern coast of Australia, in the state of South Australia.
It is bordered by two peninsulas, the Yorke Peninsula to the west and the Fleurieu Peninsula to the south east with the world renowned Kangaroo Island across the opening to the Southern Ocean on the southwest.

The capital of South Australia, Adelaide, is situated on its east coast. Other notable towns located on the Gulf include Ardrossan, Port Wakefield, Edithburgh and Port Vincent.
The gulf is also abundant with various organisms from the classes crustaecea and polychaeta, as well as various species of sea squirts and sea urchins.
The benthos is a soft sediment shelf, with species of zosteracea around the mouth of the Port River.
Kangaroo Island
Kangaroo Island is Australia's third largest island - after Tasmania and Melville Island. It is 112 kilometres southwest of Adelaide at the entrance of Gulf Saint Vincent.
At its closest point to the mainland, it is 13 kilometres offshore from Cape Jervis, on the tip of the Fleurieu Peninsula in the state of South Australia.
The island is 150 km long and between 900 metres and 57 km wide, its area covering 4 405 km² (about 1,700 square miles). Its coastline is 540 km long and highest altitude is 307 metres.
Kangaroo Island was separated from mainland Australia by a rise in sea level about 9,000 years ago. Stone tools found suggest that Aboriginal people occupied the land at least 11,000 years ago; it is supposed that they disappeared in 200 BC. Theories about the cause include disease and inbreeding, warfare, climatic change or exodus.
In 1802 British explorer Matthew Flinders named the land "Kanguroo" Island, after landing near Kangaroo Head on the north coast of Dudley Peninsula. He was closely followed by the French explorer Nicolas Baudin, who mapped much of the island (which is why so many areas have French names). Although the French and the English were at war at the time, the men met peacefully. They both used the fresh water seeping at what is now known as Hog Bay near Frenchman's Rock; the community is now called Penneshaw.
An unofficial community of sealers and others was set up on Kangaroo Island from 1802 to the time of South Australia's official settlement in 1836. The sealers were rough men and several kidnapped Aboriginal women from Tasmania and mainland South Australia. The women were forced to do the work of sealers, amongst other activities. Three Aboriginal women tried to escape and swim back to the mainland; one is on record as having survived the journey.
The biggest town on Kangaroo Island is Kingscote. Originally established at Reeves Point on 27 July 1836, it is South Australia's first official European settlement. It was later suggested that Kingscote could serve as the capital of South Australia, but the island's resources were insufficient to support such a large community, so the settlement of Adelaide was chosen.