[From the New Zealand Gazette, No. 67, December 31, 1863.]

NOTICE TO MARINERS.

General Post Office,
Auckland, 26th Dec., 1863.

THE following Sailing Directions for the Manukau Harbor, by Captain Sidney, R.N., are published for general information.

T. B. GILLIES,
Postmaster-General.

MANUKAU HARBOR.

In consequence of the changes that have taken place in the approaches to the Manukau—as so deplorably manifested by the loss of H.M.S. “Orpheus”—the Admiralty determined to have a new survey made, and directed Captain Sydney, R.N., to suspend for a time the survey of the coast of New South Wales, upon which he was engaged, and proceed to New Zealand, to re-survey and draw up fresh sailing directions for the navigation of the channels leading to the Manukau.

The following remarks and directions result from the re-examination of that locality:—

The entrance to the Main Channel appears to have shifted both to the Northward as well as to seaward, the Bar being now half a mile more to the Westward than at the time of Captain Prury’s survey in 1853. The Channel is also wider, the 8-feet bank that separated what was called the North Channel from the Main having now disappeared, if it ever existed. A ship, by attention to the lea, may now work either in or out.

The leading mark used at present is the Nine-pin Rock, in line with the tangent of the inner point of the South Head, as shewn in the sketch; but, as there is the same depth—viz., 3½ fathoms—a little to the Northward, and the banks having a tendency to extend themselves yet more in that direction, it would be better to bring the Nine-pin Rock in line either with the objects marked B or C on the sketch and plan for crossing the Bar.

After crossing the Bar, a glance at the plan will be sufficient to keep the Channel.

The South Channel seems hitherto to have been very imperfectly known, and its merits underrated; but, now that Buoys have been placed, its approach and navigation is rendered easy, and the depth of water being the same as that on the Bar of the Main Channel, and accessible at times when the latter is dangerous, it is much to be preferred.

To make the South Channel from seaward, keep the Signal-staff of Paratutai in line with the White Pile recently erected on the inner slope of the peak called Pukehurihu on the chart (properly Pukehoho) N.¼ W. This mark leads midway between the Shoals off to the South Head and the Heron Spit; and when the gap inside Poroporo (now almost an islet) and the two trees, to the right of the wooded range, come in line (as shewn in sketch) steer for it up to the outer Fairway Buoy, the crossing mark for which is the Nine-pin Rock and Parera Island in line. The outer Fairway Buoy is red with black vertical stripes, having a bell within a circular cage on top.

Leave this Buoy, or the spot indicated by the marks, on the left hand half a cable, steering 1½ points more to the Eastward for nearly four cables’ length, when the inner Fairway Buoy will be reached. This Buoy is similar to the outer one in every respect.

Leaving this also on the left hand half-a-cable’s length, two Buoys will be seen in advance to the Northward—a black one on the left, indicating the position of the Tranmere Shoal (to the Westward), and a red one on the right, 1½ cables apart. Pass midway between them, steering parallel with the shore, passing the Spit Buoy (red) on the right, and the Buoy at the tail of the Emma Bank (half black and white top) on the left, into the deep water Channel.

It is recommended that Pukehoho be chosen as the site for the contemplated Telegraph Station, the Signals to be made by two pairs of Semaphore arms, one pair above the other, one-half of the arms along their length being painted black, and the other white, which would insure their being seen under all circumstances of light and shade—against the sky, or with the land behind, the arms working at right angles to a midway between the Main and South Channels. Mr. Wing’s known ingenuity and mechanical skill would readily devise the means of working the arms by a winch from a covered-in look-out-house around the Staff.

The stump of the mast or a Beacon should be on Paratutai for the South Channel entrance mark.

The following remarks are by Mr. Wing, Pilot and Harbor-Master, made during an experience of over a quarter of a century:—

“High water at the entrance of the Manukau at full and change of moon, at 9.30. The range at springs 13 feet; neaps, 8 feet.

“The flood comes from the Northward, setting along shore from one to two knots; but when coming in contact with the banks about the Bar, it trends into the Channels, increasing its rate to four or five knots as it approaches the Heads.

“Care should be taken to guard against the cross tides about the spits and swatchways.

“The prevailing winds are from N.W. to S.W., and it seldom blows a gale from the Southward, the wind moderating as it draws from S.W. to Southward. Easterly gales are not frequent, and generally shift suddenly to the Westward, in a violent squall and very heavy rain.

“The gales rarely continue long in one quarter, and a strong breeze from N.W. or even W.S.W. (as a rule) does not cause a heavy sea in the South Channel, which can be taken with safety towards high water.

“The Bar, with such winds, generally speaking, breaks, and sometimes dangerously, towards low water; but, in case the gale gets to the S.W., the sea will break right across both Channels, but less across the South Channel, which is never at any time so dangerous as the Main. This, however, is of short duration, and seldom lasts over a day and a night, when by the morning it becomes moderate, and the South Channel free of break (even though there be considerable swell outside, and the Banks breaking heavily), and safe to enter at proper time of tide, say at half flood, or even at first quarter ebb, with a commanding breeze or steam.

“Barometer:—A low range denotes a change, and in a Northerly quarter, to be shortly attended by rain; and, in case the Barometer begins to rise, expect wind.

“When the Barometer is ranging about 30 inches steady weather may be expected from seaward.

“A high Barometer, say above 31 inches, and the land looming clear and distinct, is (as a rule) a sign of a change to the Eastward.

“I have also to remark that for many years I have observed that very clear and cloudless nights are indications of a change being at hand, either wind or rain.”

FREDERIC W. SIDNEY.
Commander and Surveyor.

Printed for the Provincial Government by HARNETT AND Co., Manse Street, Dunedin, Otago, New Zealand.