Vivonne Bay has been described in an American source as being “a bight in the coast” between Point Ellen in the west and the Eleanor River in the east which is referred to as being the ‘Mary River’ and which is located about north-northeast of Point Ellen. While the American source does nominate an eastern extremity, the official Australian source does not.
Depth
The depth of water within the bay is reported as being in the range of. The bay is reported as being suitable as an anchorage where there is a need to shelter from northerly and westerly winds. However, the bay is considered to be unsuitable as an anchorage in the case of “fresh SE winds” as “there is no space to get underway if the wind increases and a sea is raised.”
Coastline
The bay’s coastline consists of a curved sandy beach of about in length with a western end relatively sheltered from wave action by Point Ellen and an eastern end that is subject to “higher wave energy” with the result of “well-developed offshore bars” being formed and the Eleanor River being “constricted due to the large volumes of marine-sourced sand” being recycled and trapped in its mouth. Point Ellen is described as being “a grassy mound 8.5m high” that is “bordered by low rocks at its base” and is formed of a “Pleistocene aeolianite, i.e. a “dune limestone.” Two rivers, the Harriet and the Eleanor, flow into the bay with the Harriet being located at the west end and the Eleanor located at the east end. The Harriet River has an estuary coastal lagoon system at its mouth due to the local absence of the “bedrock cliffs” that dominate Kangaroo Island’s coastline.
Vivonne Bay is recognised as having a significant undertow and at times a sizeable swell, and is therefore suited only to experienced swimmers. In April 2011, two Australian tourists drowned when a large wave swept them out to sea as they posed for a photograph with their backs to the water at Point Ellen at the western end of the bay.
Fires
Vivonne Bay was impacted by bushfires in January 2020 which necessitated the evacuation of Vivonne Bay township and surrounding areas on Thursday 9th January 2020
Settlements and port infrastructure
There is some evidence that a shore-based bay whaling station operated in the bay in the 1840s. A settlement known as Vivonne Bay is located on the coastline near the mouth of the Harriet River. Port infrastructure within the bay consists of a jetty located on the west side of the bay adjoining Point Ellen and having a length of. As of 2014, navigation aids within Vivonne Bay consisted of a light on Point Ellen.