The last group was named TREGROSSE'S ISLETS.
NORTH COAST.
The ALERT struck on a shoal to the westward of Torres Strait in 1817; it seemed to be about two hundred fathoms in length, and about fifty yards broad: it is in latitude 9 degrees 52 minutes, and longitude 140 degrees 50 minutes.
In the vicinity of Cape Van Diemen there are many submarine coral banks, that are not yet shoal enough to be called reefs; that which Captain Flinders saw, and sounded upon in seven fathoms, lies in 9 degrees 56 minutes latitude, and 129 degrees 28 minutes longitude.

The Alert also passed over a shoal patch with nine fathoms in 10 degrees 1 minute South, and 129 degrees 8 minutes East.
NORTH-WEST COAST.
SAHUL BANK is but very imperfectly known, and its extent by no means so large as is laid down upon the chart.

In that interval, however, there are probably many reefs, which have been occasionally seen.

Captain Heywood saw a dry part in latitude 11 degrees 35 minutes and longitude 124 degrees 10 minutes, and there are shoal soundings in crossing it on the following parts, namely: COLUMN 1: SOUNDINGS OVER CORAL REEF IN FATHOMS.
COLUMN 2: LATITUDE.
COLUMN 3: LONGITUDE.
12 : 11 degrees 21 minutes : 125 degrees 23 minutes.
16 : 11 degrees 10 minutes : 125 degrees 27 minutes.
12 : 11 degrees 7 minutes : 125 degrees 30 minutes.
15 : 10 degrees 57 minutes : 125 degrees 34 minutes.
All of which are detached and separated by deep water.

(See Horsburgh volume 1 page 103.) CARTIER ISLAND, seen in 1800 by the ship Cartier, is a dry sand bank surrounded by a shoal extending for four miles to the northward.