This reef lies N. N. E. and S. S. W., and is about seven miles long with a breadth from one to three miles; its form is nearly that of a boot, and the outer edges are probably dry at low tide; but there was a considerable space within, where the water looked blue, as if very deep.  The origin of that class of islands which abound in the Great Ocean, under the names of Bow, Lagoon, etc., may here be traced.  The exterior bank of coral will, in the course of years, become land, as in them; whilst the interior water will preserve its depth to a longer period, and form a lagoon, with no other outlet than perhaps one or two little openings for canoes or boats.  In Mr. Dalrymple’s chart of the Pandora’s track, there is a dry bank marked on the north-west part of the reef; but this commencement of the metamorphosis was not visible to us, probably from its being covered by the tide, for it was then near high water.  In some future age, when Boot Island shall be visited, this little remark, it it live so long, may be of some interest to the geographer.

[NORTH COAST. TORRES’ STRAIT.]

I hauled up under the lee side of the reef, intending to anchor and go in a boat to sound the deep water within; but not finding any ground with 70 fathoms at a mile off, we bore away at two o’clock to make Murray’s Islands.  At three, breakers were seen four or five miles to the southward, and others, perhaps on the same reef, about three miles W. S. W. from them; in half an hour the largest of Murray’s Islands came in sight to the W. by N.; and our course being continued to six o’clock, the centre then bore N. 78 deg.  W. nearly four leagues, but the front reefs, which could not be more than half that distance in the same direction, were not visible.  We then hauled to the wind, and stood off and on till daylight [SATURDAY 22 OCTOBER 1803], when the largest island bore W. by S.

Murray’s Islands may be considered as the key to the best passage yet known through Torres’ Strait, and my route to them in the Investigator being circuitous, I wished to ascertain whether a more direct track might not be found; we therefore steered to make the north-eastern reefs, and on coming in with the breakers, ran along their south side at the distance of one or two miles.  At half past seven, the termination of these reefs bore N. N. W.; but another reef, which extended far to the south, had for some time been in sight, and a dry sand on its north end now bore S. W. by W. one mile.  In the opening between them was a small patch of coral, and several green spots in the water round it; but there appearing to be room for the Cumberland to pass on the north side, I ventured through, sounding in 20 and 23 fathoms without finding bottom.

This opening is a mile wide, and lies five or six miles, nearly E. N. E., from the largest of Murray’s Islands; it would consequently be more direct to pass through it than to follow the Investigator’s track round the north-eastern reefs; but from the narrowness of the opening and the many green spots where the depth is unknown to me, I dare not recommend it to a ship, though very practicable for small vessels in fine weather.  The dry bank on the south side of the opening will probably be covered at three-quarters flood.