Separate voyages led Bass and Flinders to the shared view that a strait separated the mainland from Van Diemen’s Land (Tasmania).
Bass left Sydney on 3 December 1797 in an open whaleboat, about 8.5 metres in length. With a crew of six he sailed south, tracing the coast as far as present-day Westernport, Victoria. Reduced provisions forced a reluctant return but Bass was convinced by the tides and swells that they were in a strait. Dogged by foul weather, this heroic voyage was duly celebrated at the time.
While Bass was away, Flinders was given permission to carry out survey work while on the colonial schooner Francis. In February 1798 Francis was sent to the Furneaux Islands, south of the mainland coast, to salvage goods from a wrecked cargo ship at Preservation Island. Flinders also came to the view that a strait existed.
If that was the case, it needed to be proven by sailing right around Tasmania and Flinders, Bass and a crew of eight set out on Norfolk (about 10.7 metres in length) on 7 October 1798 to settle the matter of the strait. Flinders and Bass worked together brilliantly. Flinders concentrated on charting and Bass explored on land, describing the animals, plants and geological formations encountered.
They sailed towards the Furneaux Islands, spending twelve days there while Flinders revised the chart made earlier on Francis.
Equipped with freshly made sealskin caps for protection against the keen winds, Flinders and Bass headed south on Norfolk, following the northern coast of Van Diemen’s Land westward.
On 3 November 1798, Norfolk entered what Hunter would later name Port Dalrymple, the estuary of the Tamar River. This was a major discovery. It was a fine harbour with good soil, fresh water and a plentiful supply of food such as kangaroos and swans. They spent seventeen days here: Flinders surveying the port, Bass making excursions into the countryside.
Sailing west from Port Dalrymple along an uncharted coast, the north-west inclination caused concern that it might have been joined to the mainland. On 9 December, Bass climbed to the peak of Albatross Island and reported that there was no land to the west or south. Truly, they had reached the western extremity of Van Diemen’s Land.
They headed south around the north-west cape (evocatively named Cape Grim by Flinders) and sailed down the west coast in four days. They sailed along the south coast, spending time in the south-east at Frederick Henry Bay and the Derwent estuary. On 3 January 1799 they sailed for Port Jackson, having proven Tasmania to be an island.
Governor Hunter named the strait after Bass, at Flinders’ suggestion. Flinders’ chart of Bass Strait and Tasmania was sent to London and published in June 1800.
In July 1799 Governor Hunter instructed Flinders to sail north as far as Hervey Bay, near Bundaberg in present-day Queensland, to locate any rivers which would allow entrance to the inland. Flinders sailed again on Norfolk, joined by his brother, Samuel, now aged 16, and a crew of eight, including Indigenous Australian Bungaree, of the Eora people. The ‘crew’ on board Norfolk included Trim, Matthew Flinders’ cat, who would remain by his side for the next five years. Although the coast was littered with rivers, Flinders found none of them and, ever sure of himself, told the Governor that none existed. This was not down to a lack of skill on Flinders part as Australian rivers are different from the European rivers he was used to.