Coronet Bay is serviced by a General Store Just to the east of the present town, a settlement was founded in 1826 from Sydney, in response to a concern for possible French territorial claims.

In that year Dumont d'Urville, in command of the corvette Astrolabe, examined Westernport, arousing suspicion during his scientific voyage.

Authorities in Sydney had also recently received reports from explorers Hamilton Hume and William Hovell, who mistakenly believed they had reached Westernport in 1824, when in fact they had arrived at Corio Bay many kilometres to the west.

Initially, a small military settlement called Fort Dumaresq was established near the present-day site of Rhyll, on the north coast of Phillip Island.

Hovell's subsequent report claiming Westernport was unsuitable for agriculture, owing to poor soil and lack of fresh water, and also the absence of any Frenchmen, led to the abandonment of the settlements in 1828.