[NORTH COAST. SAILING DIRECTIONS.]
On quitting Port Jackson, the course to be steered is N. E. by E. by compass, to longitude about 155½°, when the land will be fifty leagues off; then North, also by compass, as far as latitude 24°. Thus far no danger lies in the way; but there is then the Cato's Bank, a dry sand frequented by birds and surrounded with a reef (Atlas, Plate X), and further northward is Wreck Reef, both discovered in the future part of this voyage. Wreck Reef consists of six distinct patches of coral, extending twenty miles east and west; upon four of them there are dry banks, also frequented by birds, and the easternmost bank is covered with wiry grass and some shrubs, and is called Bird Islet. Their situations are these:
Cato's Bank 23° 6' south, 155° 23' east
Bird Islet 22 11½ 155 27
The bearing and distance of these dangers must be successively worked, and a course steered so as to leave them half a degree to the westward; but for fear of an error in the time keeper the latitude 23° 20' should not be passed in the night. It is better to make short tacks till daylight, than to heave to; and allowance should be made for a probable current of one mile an hour to the north-west. A good lookout must be constantly kept; and a confidential officer should now go to the masthead every two hours in the day and to the fore yard at night, to listen as well as look; for in dark nights the breakers may often be heard before they can be seen. It will not be amiss, if the time of the day be favourable, to make Bird Islet, which is well settled, in order to see how the longitude by time keeper agrees; and should it err, the difference, or more, must be added to, or subtracted from its future longitudes; for it is most probable that the error will continue to augment the same way, more especially if the time keeper be a good one.
[TORRES STRAIT. SAILING DIRECTIONS.]
(Atlas, Plate I.)
Having passed Wreck Reef, there are no other known dangers near the route for Torres' Strait, till we come to Diana's Bank; but as others may exist, it will be prudent to lie to, or preferably to make short tacks in the night, during the rest of the passage to the Strait. In light nights, however, and moderate weather, there would be not much risk in closely following the Cumberland's track, carrying no more sail than will allow of the ship being conveniently hauled to the wind; but if an unusual number of boobies and gannets be seen in the evening, there is strong suspicion of a bank and reef being near; and the direction which the birds take, if they all go one way as is usual in an evening, will nearly show its bearing. The longitude of Diana's Bank, according to M. de Bougainville, is 151° 19' from Greenwich; but his longitude at the New Hebrides, some days before, was 54' too far east, according to captain Cook; and it is therefore most probable, that Diana's Bank lies in 15° 41' south, 150° 25' east.
I should steer, after passing Wreck Reef, so as to go a full degree to the east of this position; and having so done, the next object of attention is the Eastern Fields, reefs which lie a degree from those where Torres' Strait may be said to commence. The position to be worked is, Eastern Fields (Atlas, Plate XIII), north-east end, 10° 2' south, 145° 45' east; and from this I would pass half a degree to the eastward. But if the Strait should be attempted without a time keeper, it will be advisable for a ship to make that part of New Guinea lying in about 10° south and 147¾° east, which may be seen as far as twelve or fifteen leagues in clear weather; and having corrected the dead-reckoning longitude by this land, to allow afterwards eighteen miles a day for a current setting to the W. N. W. The best latitude for passing the Eastern Fields, is 9° 45' to 50', steering a W. by S. course, by compass; and it will afterwards be proper, so long as there is daylight and no reefs seen, to carry all sail for the Pandora's Entrance, which is the best opening yet known to the Strait. It is formed by reefs, and is eleven or twelve miles wide, and lies, Pandora's Entrance, the middle, in 9° 54' S., 144° 42' E. and it is very possible, if the Eastern Fields be passed in the morning, to get through without seeing the breakers, and obtain a sight of Murray's Islands before dark. But it is most probable that reefs will be first met with; and should the latitude of the ship be then uncertain, even to 5', the wind must be hauled until an observation can be had, for it is by the latitude alone that the first reefs can be distinguished one from the other.
The reefs being in sight and the latitude known, a ship will steer for the Pandora's Entrance, if she can fetch it; but if too much to the north, she may pass round the north end of Portlock's Reef, and haul up S. W. for Murray's Islands, which are visible eight or ten leagues from the deck in fine weather. (See View No. 10 in Plate XVIII. of the Atlas.) It is best to approach these islands from the N. E. by N., following the Investigator's track, and to anchor the first night on the north side of the largest island, or otherwise under the reefs which lie to the north-east; but if neither can be reached before dark, haul to the wind and make short trips till daylight, in the space between these reefs and Portlock's Reef.
Murray's Islands should not be passed, or quitted if the ship have anchored there, later than ten or eleven o'clock in the morning; because the sun will be getting ahead and obscure the sight before another good anchorage can be secured. On passing the islands, keep the reef which lies five miles to the north about a mile on the starbord hand, steering W. ½ S. by compass, with a boat ahead; for in this part there are many tide ripplings scarcely to be distinguished from the reefs. Having passed the ripplings, haul a point more to the southward; and after having run eight or ten miles, from the time that the largest island bore south, there will be very few reefs to the northward, and Darnley's Island will be seen. On the larbord hand there will be a great mass of reefs: and these it is necessary to follow at the distance of two or three miles, steering mostly W. S. W., and gradually more southward as they are found to trend. Some small patches will occasionally be met with; but having the boat to go ahead, and the commander, or a careful officer looking out aloft, the Investigator's track between them may be safely followed. The leading mark in all this part of the course, is the line of the great south-eastern reefs; and the situation of the ship may be known at any time, by laying down cross bearings of Murray's and Darnley's Islands on the chart, allowing, if the ship's head be westward and the compass on the top of the binnacle, 5° of east variation.