The peninsula thus formed was honoured by the appellation of Cobourg, after His Royal Highness Prince Leopold.
During the day large smokes were observed on the south horizon, without any appearance of land near them.
1818.

May 1.
On our way out we anchored under one of Sir George Hope's Islands, which, on the occasion of our landing upon it the next morning (1st May), was called May-day Island: it is about two miles long, and nearly the same distance across; its formation appears to have been originally of sand that has accumulated upon a rocky basis, and has gradually grown into an island; it is thickly covered with a forest of dwarf trees and impenetrable brushwood.

Some recent impressions of a human foot on the sand below high-water mark were seen, and several old fireplaces, and one or two of more recent date were observed, around which were strewed the remains of shell-fish repasts; the natives, however, did not make their appearance.
When returning on board we endeavoured to pass out between May-day and Greenhill Islands, but a bar of sand that appeared to stretch across obstructed our progress: the weather being fine and the sea very smooth, we endeavoured to force her over, but as we did not succeed, we anchored for the night near our former position, to the eastward of Mount Roe.
May 2.
The next day we passed out between the Mount and Greenhill Island, and at night anchored on the south side of May-day Island, at eight miles distance from it.
May 3.
The following day we made some progress to the South-East, and by the afternoon obtained a glimpse of some land bearing between South 3 degrees West and South 18 degrees East.
May 4.
And at sunset the next evening the lowland was traced as far to the southward as South-South-East, upon which several detached hills were seen which probably may have some connexion with Wellington Range.
May 5.
The next day the cutter was anchored within a mile and a half of the south point of a considerable opening, which the boats were prepared to examine.
May 6.
And at daybreak we commenced its exploration, but the greater part of the tide was expended before we reached the entrance, which is fronted by a bank of mud on which there was not more than twelve feet water; the depth, however, increased after we entered the river to four and five fathoms; and as we proceeded up we found the channel to be seven and eight fathoms deep.

The banks on either side were very low; they were composed of a soft mud, and so thickly lined with mangroves as to prevent our landing until we had pulled up for seven or eight miles.

At ten o'clock the flood ceased and the ebb, setting with considerable strength, prevented our proceeding higher up: here we landed, and after spending some time in taking bearings and examining the country, we returned to the cutter, which we reached early in the afternoon.
The banks where we landed were about two hundred yards apart, but were so low and without a hillock to ascend or a tree to climb to enable us to obtain a view of the country, that we could form but a very slight opinion of the place.