ROWLEY’S SHOALS consist of three separate reefs, the westernmost is the Imperieuse, the middle Clerke’s, and the north-easternmost the Mermaid’s. The Imperieuse is ten miles in length from north to south, and its greatest breadth five miles: it is surrounded by very deep water and near the eastern edge, in latitude 17 degrees 35 minutes, and longitude 118 degrees 51 minutes, are some dry rocks. Clerke’s Shoal (south end in latitude 17 degrees 28 minutes, longitude 119 degrees 18 minutes) extends to the north-west, and probably joins the Minstrel’s Shoal, which is described below, and, if this is the case, trends North-North-West 1/2 West for seventeen miles. The south end of Mermaid’s Shoal is in 17 degrees 12 minutes South, and 119 degrees 35 minutes East, and extends to the northward for seven miles; but its termination in that direction was not seen. The edges of all these reefs are steep to; and no bottom was obtained with one hundred and eighty fathoms. Within the reefs, however, there is a bank of soundings of the depth of from one hundred and seventy to one hundred and twenty fathoms. (See Horsburgh volume 1 page 101.)
MINSTREL’S SHOAL (see Horsburgh’s Supp. page 52) its north-east end is in 17 degrees 14 minutes South, and 118 degrees 57 minutes East, or 5 degrees 28 minutes East by chronometer, from the coast of New Holland in latitude 23 degrees 10 minutes South. The longitude of that part of the coast by my survey, is 113 degrees 42 minutes; this will make the Minstrel’s Shoal in 119 degrees 10 minutes, which agrees very well with Clerke’s Reef, the centre reef of Rowley’s Shoals, of which it is certainly the north end; so Captain Horsburgh also supposes.
A ship called the LIVELY was wrecked on a coral reef in about 16 degrees 30 minutes South, and 119 degrees 35 minutes East.
RITCHIE’S REEF, or the Greyhound’s Shoal. The situation of this reef is recorded by Captain Horsburgh (see Supp. page 38) to be in latitude 19 degrees 58 minutes, and longitude 114 degrees 40 1/4 minutes; but, by a letter published in the Sydney Gazette by Lieutenant Ritchie, R.N., the commander, it would appear to be in 20 degrees 17 minutes 40 seconds, longitude by lunars 114 degrees 46 minutes 6 seconds.
ROCK OFF VAN DIEMEN’S LAND.
The Russian ship RURICK, in 1822, saw a dry rock above water off the south-east coast of Van Diemen’s Land, in latitude 44 degrees, and longitude 147 degrees 45 minutes.
A rock was also seen by the ship LORD SIDMOUTH in 1819, in latitude 43 degrees 48 minutes, and longitude 147 degrees 15 minutes.
DIRECTIONS FOR THE PASSAGE WITHIN THE REEFS THROUGH TORRES STRAIT.