"The positions of the various points and islands are so correctly laid down on Flinders' chart, that the skilful navigator will at once know his exact situation by cross-bearings.
"The anchorage in Port Lincoln itself is not so safe as in Boston Bay, and more difficult of access, especially in the winter months, when the winds are strong from the south-west, and in the summer months it is quite open to the north-east. In working up, a vessel may stand close in to the eastern shore, and to within half a mile of the western, but should not attempt to pass between the two Bicker's Islands, as there is a reef running from the northernmost island nearly across to the other.
"Vessels from Adelaide, bound to Boston Bay, after arriving at Althorpe's Island, should shape a course so as to pass between the Gambier Islands and Thistle's Islands. There is a small island bearing west five miles from the south end of Wedge Island, the largest of the Gambier group, which is not laid down in Flinders, which should be left on the starboard hand. Bring the highest part of Thistle's Island to bear west, distant about six miles, and in twenty-two fathoms water, and a north-west half-west course will carry you through midway between the Horse-shoe Reef and the rocks which lay off the north-west end of Thistle's Island, and in the direct track for Cape Donnington. The passage between the reefs is about three miles wide, and ought not to be attempted in the night, as the tides set directly across the channel. There is very good anchorage on the north-east side of Thistle's Island, well sheltered three-fourths of the year. Bring the rocks before-mentioned to bear north-north-west, and two remarkable sand hills south by west, and you will lay in five fathoms, one mile off shore--north end Thistle's Island west by south. Should the wind be so strong from southwest or west-south-west, so that a vessel from the eastward cannot carry sail sufficient to fetch up to Cape Donnington, or under Thistle's Island, it would be advisable to bear up for Hardwick Bay; passing to the eastward of Wedge Island, come no nearer to the shore of York's Peninsula than two miles, until you arrive within five miles of Corny Point, when you may haul in for that point, rounding it a distance of half a mile, you may bring up in five fathoms, one mile from shore: Corny Point bearing west. Vessels from Sydney, bound to Port Lincoln, may pass through Backstairs Passage, and proceed according to the foregoing directions, or by keeping well to the southward, pass outside Kangaroo Island, until they arrive in longitude 136 degrees E., when they may shape a course either to pass between Gambier's and Thistle's Islands, or else for Cape Catastrophe, taking care to give the Neptune Islands a wide berth, and then proceed according to either of the foregoing directions."
To this extract which refers exclusively to the navigation of Spencer's Gulf, I may add, that Boston Island lies immediately opposite to the bay, and that there are two channels of entrance round the island, through which vessels of the largest size can pass with any wind or in any weather, for the harbour is so sheltered by the headlands forming the entrance, that the swell of the sea is broken before reaching it.
The high ground which almost surrounds Boston Bay, protects it in like manner from the winds, more especially those coming from the west and southwest, in which directions some of the hills attain the height of several hundred feet.
The depth of water in the central parts of the Bay is about twelve fathoms, varying from five to seven at the distance of less than a quarter of a mile from the shore all round; whilst at Boston Point, where the town of Boston has been laid out, there is a depth of two, three, and four fathoms, at about a boat's length from the land. The bottom consists in some places of mud, in others of shells and sand, so that the anchorage is safe.
The tide sometimes rises seven feet, but that is considered a high tide, the ordinary rise not being more than five; this depends, however, on the outward state of the Gulf, and the quarter from which the wind may happen to be blowing.
In the summer season, the land and sea breezes blow very regularly, for three weeks or a month at a time. They are then succeeded by strong winds from the south-west, that last for three or four days, and are sometimes very violent. In winter these interruptions to the usual calm state of the weather are more frequent, but the harbour is little influenced by them; taking it altogether, indeed, as a harbour, it is unquestionably as safe and commodious as any in the world, and it is deeply to be regretted, that its position, of which I shall have to speak, and the nature of the country behind it, should be any drawbacks to its becoming one of the most important ports on the Australian Continent.
In the vicinity of Port Lincoln, the land is of very varied character. To the west and south-west it is poor and scrubby, covered with a diminutive growth of she oak (Casuarinae) or dwarf gumtrees (Eucalypti), or it is wholly destitute of timber; but along the line of hills, stretching to the north, at a short distance from the shores of the Gulf, there is an improvement in the soil. The pasture is well adapted for sheep, and there are isolated valleys in which the soil is very good and fit for cultivation; but this kind of country only occupies a narrow strip of about ten miles, and although tracts of available land have been found in the interior, and it has been ascertained that water is not deficient, it must still, I fear, be considered as a very inferior district. As regards Port Lincoln itself, the inhabitants procure their water from a spring, on the sea-shore, which is covered by every tide. This spring does not appear to undergo any sensible diminution, even in the height of summer, and is stated to be so copious, that it would yield a most abundant supply.
It has been reported, that strong indications of the presence of copper have been found in the neighbourhood of Port Lincoln, and this report may be correct. The discovery of mines there, would at once raise the harbour to importance, and make it the resort of shipping. Mines might be worked at Port Lincoln with more advantage perhaps to the province, than where they have been already in operation, for it admits of great doubt whether the benefit from the distribution of wealth from mining speculations, makes up for the interference of such speculations with other branches of industry. Unless some local advantage, of the kind to which I have alluded, should give this noble harbour an impulse however, it would appear to have but little prospect of becoming a place of importance, for although Spencer's Gulf penetrates so deep into the northern interior, the country is altogether unprofitable, and although there is depth of water sufficient for the largest ships to the very head of the Gulf, yet, as far as our present knowledge extends, it is not probable that it will be the outlet of any export produce. It is to be remembered, however, that if there should be minerals in any abundance found on the Mount Remarkable special survey--the ore must necessarily be shipped, from some one of the little harbours examined by the Lieutenant-Governor during his survey of that part of Spencer's Gulf--In such case, Port Lincoln will be brought more immediately into notice.