Cape Spencer is located about 125 kilometres (78 miles) south west of the municipal seat of Maitland in the gazetted locality of Inneston.[3] It is the most south westerly point of the Yorke Peninsula coast and defined by Flinders as being the eastern side of the mouth of Spencer Gulf.[4] It is the termination for a pair of coastlines - the western coastline extending from Corny Point in the nouth and the southern coastline extending from Troubridge Point in the east.[5] It is described as appearing ‘as a cone with a ledge of rocks at its base’ when viewed from the south.[1] Cape Spencer is accessible via a walking trail from within the Innes National Park. Access extends to the area around the Cape Spencer Lighthouse where views of both the adjoining coastline and nearby islands are available and the presence of interpretative signage provides information about the locality’s maritime history.[6]
Formation, geology & oceanography
Cape Spencer was formed when the sea reached its present level 7,500 years ago after sea levels started to rise at the start of the Holocene.[7]
The cliff line which includes Cape Spencer consists of base strata of both Gleesons Landing Granite and Tourneforte Metadolerite with an overlay of a Bridgewater Formation calcarenite rock.[8]
The water adjoining the wave-cut platform at the base of Cape Spencer drops to a maximum depth of 14.8 metres (49 feet).[9]
The current concrete lighthouse was built in 1975 to replace a small automatic beacon erected in 1950.[10] The cape is also the site of a high frequencyradar station which is used to collect data about wind direction and wave height.[11]
Protected area status
Cape Spencer has been located within the protected area known as the Innes National Park since the park's declaration in 1970.[12] As of 2012, the waters surrounding its shores are within the boundaries of a habitat protection zone within the Southern Spencer Gulf Marine Park.[13]
^Hydrographic Department, Ministry of Defence (1983). Gulf of St Vincent and approaches (chart no. 1762). (reproduced by the Royal Australian Navy Hydrographic Service).
^South Australia. Department of Marine and Harbors (1985), The Waters of South Australia a series of charts, sailing notes and coastal photographs, Dept. of Marine and Harbors, South Australia, pp. Charts 23, ISBN978-0-7243-7603-2