|11, -1.9041, 32.4138|
|Territorial authority||Avoca Cobalt Borough|
|• Provincial electorate||Avoca|
|• National electorate||Cobalt Island|
|Demonym||Cobalite (local), Cobalt Islander (official)|
|• Estimate (2016)||9,846|
|• Census (2012)||9,271|
|Telephone Code||057 766, 057 767|
Cobalt Island is the largest coastal island of St Austell, Vodeo. Located in Caipah Harbour, 13 kilometres (8 miles) east of Saviso, the island forms a natural breakwater for the shallow waters and wetlands of the harbour, which shares the island's Beha name, Caipah. The island and its outlying islands (chiefly Nicole, Faron, Poynes, and Seger Islands) are located in close proximity to the Vodean mainland, making navigation through the Sthilldina and Driscoll Channels very difficult.
With a population of nearly 10,000 it is Vodeo's third-most populous island, behind Staha Island in Schellingen and Vauxhall Island in Holme. The island's population is mainly concentrated on the western side of the island in the suburbs of Avoca, Prospect, Tobico, Caporahan, Bottle Beach, and Plumhoe; however, other notable towns on the island include Henderson, Boharinca, Zyuwiln Bay, North Beach, and Zenith Head. Avoca is the largest suburb on the island, and is the seat of the Avoca Cobalt Borough Council.
The island is notable for being the location of the Cobalt Island Raceway, the oldest motor race circuit in Vodeo. It is one of the major circuits of Vodean Touring Car Championship, which each year sees the population of the island swell to around 30,000.
Part of the southern end of the island between Sthilldina Entrance and Dickeys Point, and surrounding the town of Zyuwiln Bay, is reserved as the Cobalt Island Conservation Area. The park was established in 1997 to protect against increasing development on the island.