Bass Strait is a sea strait separating Tasmania from the south of the Australian mainland (Victoria in particular). The first European to discover it was Matthew Flinders in 1798. Flinders named it after his ship's doctor George Bass. Approximately 240 km wide at its narrowest point and generally only around 50 metres deep, it is believed to have been almost dry during the last ice age. It contains many islands, with King Island and Flinders Island home to substantial human settlements.
Like the rest of the waters surrounding Tasmania, and particularly because of its limited depth, it is notoriously rough, with many ships lost there during the 19th century. A lighthouse was erected on Deal Island in 1848 to assist ships in the eastern part of the strait, but there were no guides to the western entrance until the Wilsons Promontory Lighthouse was completed in 1859, followed by another at Cape Wickham at the northern end of King Island in 1861.