It was on March 6th that the exploration of Spencer's Gulf commenced. As the ship sailed along the western shore, the expectations which had been formed of a strait leading through the continent to the Gulf of Carpentaria faded away. The coast lost its boldness, the water became more and more shallow, and the opposite shore began to show itself. The gulf was clearly tapering to an end. "Our prospects of a channel or strait cutting off some considerable portion of Terra Australis grew less, for it now appeared that the ship was entering into a gulph." On the 10th, the Investigator having passed Point Lowly, and having on the previous day suddenly come into two-and-a-half fathoms, Flinders decided to finish the exploration in a rowing boat, accompanied by Surgeon Bell. They rowed along the shore till night fell, slept in the boat, and resumed the journey early next morning (March 11th). At ten o'clock, the oars touched mud on each side, and it became impossible to proceed further. They had reached the head of the gulf, then a region of mangrove swamps and flat waters, but now covered by the wharves of Port Augusta, and within view of the starting point of the transcontinental railway. The disappointment was undoubtedly great at not finding even a large river flowing into the gulf. The hope of a strait had been abandoned as the continually converging shores, shallow waters, and diminishing banks made it clear, long before the head was reached, that the theory of a bifurcated Terra Australis was impossible. But as Flinders completed his chart and placed it against the outline of the continent, he might fairly enjoy the happiness of having settled an important problem and of taking one more stride towards completing the map of the world. The Investigator travelled down by the eastern shore, once hanging upon a near bank for half an hour, and by March 20th was well outside. The length of the gulf, from the head to Gambier Island, Flinders calculated to be 185 miles, and its width at the mouth, in a line from Cape Catastrophe, 48 miles. At the top it tapered almost to a point. The whole of it was personally surveyed and charted by Flinders, who was able to write that for the general exactness of his drawing he could "answer with tolerable confidence, having seen all that is laid down, and, as usual, taken every angle which enters into the construction." The next discovery of importance was that of Kangaroo Island, separated from the foot-like southern projection of Yorke's Peninsula by Investigator Strait. The island was named on account of the quantity of kangaroos seen and shot upon it; for a supply of fresh meat was very welcome after four months of salt pork. Thirty-one fell to the guns of the Investigator's men. Half a hundredweight of heads, forequarters and tails were stewed down for soup, and as much kangaroo steak was available for officers and men as they could consume "by day and night." It was declared to be a "delightful regale."