At the entrance of the basin the high rocky character of the west shore is superseded by low mangrove banks, with here and there a detached hill rising from a plain of low marshy land, that, at the time of our visit, was covered with a salt incrustation, occasioned by the evaporation of the sea, which, apparently, had lately flooded the low lands to a great extent:  some of these plains are seven and eight miles in diameter.  The hills rise abruptly; those we examined are of sandstone formation.  The basin is very shoal, but there is a narrow channel in the centre, with from five to nine fathoms water.  The shore, opposite the Bastion Hills, is low, and the gulf trends gradually round to the South-West for five miles, when it is contracted into a narrow communication, called The Gut, leading to an interior shoal basin, strewed with low marshy islands, which the tide covers.  This basin terminates to the southward in a narrow stream, winding under the base of Mount Cockburn; and there also appeared to be several others falling into the basin more to the westward.  The water was salt at the extremity of our exploration.  The Gut leading to it is two miles long, and not so much as a quarter of a mile wide:  in some parts we had nineteen fathoms, but in others it was deeper; it runs through a chasm in the hills, which rise abruptly, and occasionally recede and form bights, in which, in the wet season, the rains form some very considerable mountain torrents.  No fresh water was seen in any part of the gulf; but as it was near the end of the dry season when we were there, it might probably be found in a more advanced season in every part of the western side, where the land is high and the gullies numerous:  there is, however, no durable freshwater stream without the Gut.  An alligator was observed swimming about, but very few fish were noticed.

The coast extends from Cape Dussejour to Cape Londonderry, a distance of ninety-five miles, without an opening, and with but few sinuosities of any consequence.  The coast is chiefly rocky, with here and there a few sandy beaches:  but the shore generally is open and exposed:  there are many parts, however, where a boat might land; particularly behind BUCKLE HEAD, and a little farther on at REVELEY ISLAND:  at the latter place there is a gully in the hills, at the back of the bay, which may probably produce fresh water:  this bay is near Captain Baudin’s MOUNT CASUARINA, a flat-topped hill, that is conspicuous from the sea.  The mount is only visible between the bearings of South and West-South-West, and may be seen at the distance of seven or eight leagues.  It is situated at six miles from the shore, in latitude 14 degrees 23 minutes 15 seconds, and longitude 127 degrees 36 minutes 50 seconds.