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. It is in 12 degrees 29 minutes South, and 123 degrees 56 minutes East, by chronometer. Captain Heywood in 1801 saw the following reefs. The centre of one in latitude 12 degrees 48 minutes, and longitude 124 degrees 25 minutes; and the other in 13 degrees 29 minutes, and 124 degrees 5 minutes. HIBERNIA SHOAL, seen by Mr. Samuel Ashmore, Commander of the ship Hibernia, consists of two small sandbanks in the centre of a shoal, four miles in extent, lying in an east and west direction. It is in latitude 11 degrees 56 minutes, and longitude 123 degrees 28 minutes, by chronometers. Mr. Ashmore also saw another shoal in 1811, the particulars of which are detailed in the following letter. "The north-east end of the shoal, fell in with on the 11th June, 1811, by a good noon observation, is in 12 degrees 11 minutes South, longitude by chronometer 122 degrees 58 minutes 30 seconds (allowing the south head of Port Jackson to be in 151 degrees 25 minutes 25 seconds). To the westward of the barrier of black rocks, that presented themselves to our view, were several sandbanks, the highest of which, on the east end, appeared to have some vegetation: the rocks in general were six or eight feet above the water and the surf broke violently on the North-East and South-East points in view. The shoal trends in a West by North direction for six or seven miles," It is distinguished on the chart by the name of ASHMORE'S SHOAL.