Between Cape Bougainville and Cape Voltaire is the ADMIRALTY GULF. It is twenty-nine miles wide and twenty-two deep, independent of Port Warrender. This gulf is thickly strewed with islands and reefs: a group off Cape Voltaire was seen by the French and named by them the INSTITUTE ISLANDS, the three principal of which, of flat-topped shape, are called Descartes, Fenelon, and Corneille; besides these the Montesquieu Group, and Pascal and Condillac Islands, were distinguished. On the eastern side of the gulf, near the shore, are OSBORN'S ISLANDS, which are high and rocky: the southernmost is remarkable for its steep, precipitous form, and for its resemblance to Mount Cockburn in Cambridge Gulf. There is also a conspicuous high bluff on the principal island, which appears to have been seen by the French.
In the offing is CASSINI ISLAND; it is rather low and level, and surrounded by cliffs and rocky shores: on the eastern side are four sandy beaches, which are very much frequented by turtle: a reef projects off its north end for a mile and a half. The anchorage is good near the island, but the water is very deep. The situation of its centre is in latitude 13 degrees 55 minutes 5 seconds, and longitude 125 degrees 42 minutes.
PORT WARRENDER is an excellent port, and affords good anchorage in the bay round Crystal Head, in which a vessel is quite land-locked; but equally secure anchorage may be had for five miles higher up the port, in from four to seven fathoms, mud. It extends for six miles farther, but the depth in some parts is not more than two fathoms.
At eleven miles from the entrance, the port is separated into two inlets, which wind under the base of a dividing range of high, steep, and wooded hills; these run up for five miles higher, when they become mere mangrove creeks. There is probably another inlet on the east side of Port Warrender which we did not examine, since it appeared to be less considerable in size, and important in appearance, than the arm which we had examined. CRYSTAL HEAD is in latitude 14 degrees 28 minutes, and longitude 125 degrees 55 minutes 30 seconds.
WALMESLY BAY appeared to be a good port also, but it is open to the eastward. We did not enter it.
CAPE VOLTAIRE is the extremity of a promontory, extending for more than twenty miles into the sea, and separating the Admiralty Gulf from Montagu Sound. There is a flat-topped hill near its extremity, in latitude 14 degrees 14 minutes 30 seconds, and longitude 125 degrees 40 minutes 12 seconds; and, at three miles more to the southward, a peaked hill; its shores on either side are rocky, and indented by bays. At one part the width across to Walmesly Bay cannot be more than a mile and a half.
The MONTALIVET ISLES, about six leagues from the main, consist of three rocky islands; they are visible for six or seven leagues from the deck: the north-easternmost is in latitude 14 degrees 13 minutes 40 seconds, longitude 125 degrees 19 minutes 30 seconds.
MONTAGU SOUND extends from Cape Voltaire to the north end of Bigge's Island, a distance of thirty-one miles, and is from eleven to twenty miles deep. It is fronted by a range of islands; the outer range, which is eight miles within the Montalivet Isles, was called PRUDHOE ISLANDS; besides which there were several scattered about the sound, and some of larger size near the main: of the latter are KATER'S and WOLLASTON'S. They are of a very rocky character, and furnished with but a poor and shallow soil, although the surface is thickly covered with small trees, growing most luxuriantly. WATER ISLAND, to the north-east, in latitude 14 degrees 21 minutes, and longitude 125 degrees 32 minutes 25 seconds, was visited by us, as was also CAPSTAN ISLAND, in the south-west corner of the sound. The latter island is in latitude 14 degrees 35 minutes 20 seconds, and longitude 125 degrees 16 minutes 20 seconds. They are both rocky, and destitute of any soil but what is formed by the decomposition of the vegetables that grow upon the island. The channels between them appeared to be clear and free from hidden danger. The depth among the islands is from ten to fifteen fathoms on a muddy bottom; but the anchorage is better between Kater Island and the promontory that separates it from Walmesly Bay, than any other part. It is a very fine port, particularly near the bottom, in SWIFT'S BAY, where the depth is from four to five fathoms at low water, It is high water at full and change in Swift's Bay at twelve o'clock, which is two hours and a quarter later than in Vansittart Bay: the tide rose eighteen feet, whereas in Port Warrender its rise was only six. The islands off the north-east end of Bigge's Island are more numerous than in other parts of the sound: they were only seen at a distance, and too numerous to give correct positions to. BIGGE'S ISLAND is fourteen miles long, and from six to seven broad; it is of moderate height, and rocky character: its south end appeared to be thickly wooded. A flat-topped hill near the shore of Scott's Strait is a remarkable object, and may be seen six or seven leagues off. It is in latitude 14 degrees 39 minutes 20 seconds, and longitude 125 degrees 10 minutes 20 seconds.
SCOTT'S STRAIT is a channel separating Bigge's Island from the main: it is thirteen miles long, and from three to one and a quarter broad. It is of irregular depth, and has some rocks in mid-channel, which are dry: the deepest channel is near the eastern shore, the depth being from ten to fourteen fathoms. The strait does not terminate until you are to the westward of Cape Pond, for there are several islets off the south end of Bigge's Island, and a considerable reef, through which, although there may be deep channels, yet they must be narrow. Off the north-west end of Bigge's Island are several rocky islets; the outer ones were seen by me in the Bathurst (see above): they are the MARET ISLES of Commodore Baudin; they consist of four or five principal islands, of about two miles in length, besides as many more of very small size off the south extremity of the group. The northern point of the northernmost island is in latitude 15 degrees 7 minutes 15 seconds, and longitude 124 degrees 56 minutes 40 seconds. The group is fronted on the north-west side by a considerable reef, extending North by East 1/2 East for seven miles; the outer edge being three miles and a half to the westward of the group.
YORK SOUND is fourteen miles wide and ten deep: it is contained between Cape Pond and the northern extreme of the Coronation Islands. It is spacious, but the bottom, in the middle, is rocky: there is, however, very good anchorage near the Coronation Islands; and there is also, possibly, as good on the eastern shore to the south of CAPE POND, which has a rocky island immediately off it, the situation of which is in latitude 14 degrees 43 minutes 20 seconds, and longitude 125 degrees 9 minutes 25 seconds.