The Moyne River rises near Stonefield, from the edge of the lava flows west-southwest of Penshurst.

The river originally spilled into the Bass Strait, south of the town of Port Fairy, through a series of narrow channels that led westward from the site of the present-day mouth.

At that stage, the southern outlet of the Moyne, the Back Passage, was narrow and the opening to the sea was often too rough for boats to leave or enter the port; the main eastern outlet was blocked by a shallow sand bar.

Training walls constructed in the 1870s curve from the northern part of Griffiths Island through the sand bar.

[1] Media related to Moyne River (Victoria) at Wikimedia Commons This article about a location in Barwon South West (region) is a stub.