MANUKAU HARBOUR. Her Majesty's Surveying Vessel Pandora, At Sea, May 3rd, 1853.

Daily Southern Cross, Volume X, Issue 643, 26 August 1853, Page 2

MANUKAU HARBOUR. Her Majesty's Surveying Vessel Pandora, At Sea, May 3rd, 1853.

Sir, — I hire the honour to forward, for the information of Hit Excellency the GoTernor, this report upon Manukau harbour, the Surrey of which was completed to-day, and I have the greatest satisfaction in informing Hii Excellency that there ii a straight and direct channel of considerable breadth into this harbour, through which H.M.S. Pandora patted to-day at near low water, in 4} fathoms. At spring tidei, low water, there is not lets than 3£ ft thorns, at higb water not lets tban SJ. The straightest line out of Manakau having the , three most conspicuous objects in transit, namely, the Ninepin, the extreme of Paralutai, and the extreme of Poponga, was the course we steered out, which I felt so sure from observation was a clear channel, that we carried studding-sails over it, at low water. Thereby divesting the entrance of Manukau harbour of a great proportum of a bank, that hat hitherto been laid down as facing the harbour. There it certainly least water on the position of this bank than elsewhere, nor do I deny that it is possible there may have been still less water, but it has not been crossed before, except, I believe, by vessels surotiied to find themselves in safety on the other side.* Hitherto there appears to have been little known of the access to this harbour, or ot the depths of the channels within, and a strong prejudice has existed against it, for reasons I will attempt to clear up, for some of these we are indebted to accidents as proof of its practicability. First. — It is a common error to believe that the breakers extend connectedly across the Heads, because, when viewed from Poponga. the middle bank, which, is always breaking! faces this view. Secondly.— From, the land about Paratutai it will appear to break acrosi alto, for the Orwell and middle bank would here over-lap. A similar cause occurt when viewed from the foot of the South head, but, once in the channel, between the Heads, and the sea it open before you. Thirdly.— 'lt appears that the Eclair, and small traders have fallen into the same error, and have preferred waiting for an opportunity to pars through a shoal and narrow passage near the Somh head, which frequently detained them for days, when such vessels could with facility have beat down with the tide, having never less than half a-mile in the channel, and increasing in breadth from Paralutai outwards. Now, Sir, in regard to changes that may have taken place in the entrances to Mtnukau, although the above reasons explain away the want of belief in a fair channel, they in no degree affect the accuracy of the survey of Mr. Ormtby, or the more recent survey of Mr. Smith of H.M S. Acheron. The former gentleman delineates a channel after passing the middle bank, without, it appears, having intended to go directly out. Mr. Smith bat corroborated it, and added many sounding*, and he thews also a North channel, of ha f a mile wide, of three fathoms, but having given us the cuter bank without soundings, we conclude he did not cross it either ; it then becomes a question whether this bat undergone a change,— if to, a change of great benefit, giving a fairer channel in, —and whether the Northern channel, which appeared to us to be breaking comiderably at the depth given, it not in consequence less eligible. On entering Manakau through the O'msby channel, when there was a tolerable South swell, we remarked that the position of the outer bank did sot break. Subsequent observations by officer* stationed at the Heads confirmed this, and the master and myself crossed the -outer bank in a boat, but an unusual fog coming on we were thrown entirely out of the line, being uruble to see Para tutai; we, however, crossed into deep water over that shoaler portion of the bank near the North channel, having only 1 1 feet (low water, springs) We found, on laying down the work, we had crossed to the Northward, and therefore it did not deter ut from taking the straight channel out in the Pandora,— which we did on the day after a westerly gale, without a breaker. I have been thus particular in bringing this por tion of the report to notice, in order that unneces* tary expense may not be incurred by establishing a fixed light home, where it might posiibly be an advantage to shift it. My opinion it, that it it quite potsible that the configuration of sand banks subjected to the j >mt influence of tide*, freshes, and gales are liable to vary, and yet I think it more thin probable that the present straight channel should remain, as it has taken (if, indeed, it ever shifted) its natural course, the direction of the Harbour. I Betides this channel into Manukau, I have i already mentioned another laid down to the Northward, half a mile wide, having 3 fathoms water, but I should neither recommend it, or the small intricate channel to the Southard, since we have a direct and deeper. The soundings, on approaching Manukau from ■eaward, decrease very gradually. The extreme of the outer bank channel is three miles from the heads, (he depth of water in steering in between the Orwell and South bank varies from 8 to 16 fathoms,— these banki are tteep too, and alwayt shewing. In the channel only it breaks in gales at the shoalett part ; in ordinary winds it certainly doe* not. During three weeks the officers were employed about the Heads, it was not teen breaking, although strong winds prevailed. At the mouth of the harbour the channel decreases in width (half a mile) ; this it off Puralutai or North head, and here the tide runs 4 knots at springs; at the outer channel tides rarely reach two. The South Head is a mile within the North Head, and has a tpit extending half way across towards Paratutai, but there it now ft clear, deep channel toimrds Kurnngahapi, with a bold shore. | Off Huia, on the North shore, three miles, from Patatutai, is anchorage in five fathoms, but the anchorage after rounding Karangahupi is the brat in oil winds. Or if it m intended to go to the Waiuku oi Ptipakura, there is anchorage within | Kauri point opiioiite.

From theie points Manukau expands to a breadth of 15 miles by 12, hiving three channels navigable for vessels of any tonnage to three equi-distant and most valuable district*, name'y, Onehunga, Papakura, and Waiuka. These channels are. with small exceptions, nearly straight, and having dry banks on either side at low water, they offer a sheltered anchorage at any point. The channels continue their depth to within the Heads of Waiuku and PapaKura, and close up to O.iehunga. There are, besides, two deeper channels leading along the North shore, the one branching off Onehung* middle channel at Shag Point (Okewha) to tbe Wahau portage, and joins the middle Onebnnga channel off Matengahe or Cape Horn, though at thi- point it is only navigable at high water. The other oucer Onebanga channel comes up direct from Karangahapi, and would hare been the best channel to Onehunga, but it fails in depth where it enters the mid channel ; iris useful to the lands around Pukitutu, and indeed is generally aTtilable, as it would have 22 feet at high water where it is most difficult. The general nature of the bottom of all the channels is a greenish sand and mud, good holding ground. The tides within them average at springs 2} knots ; there are no- rocks, and no uneven ground, and the banks, being soft sand and shells, ■re not likely to injure a vessel on touching. One tide will suffice to carry a vessel from the heads, with a leading wind, to any of tbe above districts. It will be obierved, these remarks are tutted for vessels of any burden, but the Manukau flats can be traversed by boats according to the tides, and, unlike the banks outside, here we have the smoothes? water over them, the tide taking the course of the channels. The banks are generally covered soon after the firnt quarter flood, but they vary in height, and some are never uncovered, especially those facing the Waiuku channel, where there is generally 4 feet at low water, and only small spots that dry. Having made these general observations on the channels, I come to their more immediate description. Onehunga middle, or main, channel leads along the coast from Poponga. A flat extends from Karangahapi, off which is the anchorage. From Karangahapi there ia a straight channel to Shag Point (Okewha) one third of a mite broad, with 4£ fathoms at low water. The distance from Poponga to Shag Point being 4$ miles. Here the channel divides, the inner one, along the Muta Karaka, having a depth of 12 fathoms near the portage, but, as before mentioned, difficult at Cape Horn. At Shag Point (Okewha) the channel fplita, the inner running along the coast. The main channel here is scarcely a i of a mile, and strikes off to tho westward, and gradually curvei again to Cape Horn ; just before reaching Cape Horn there is least water; it is where the three channels join, at 13 feet, low water. (Matengahe,) or Cape Horn, is 2| miles below Onehunga, it is steep too, as also are iome of the other points before reaching Onehunga, and as the flat extending from the town rennders shipment very inconvenient, I think these Head lands, will be valu able, besides being about the nearest points to Auckland. And the anchorage ia wider than that immediately off the lower end of Ooehunga, where there is however a pool of 3 fathoms at low water. The general anchorage for Onehunga, would be below the White Cliff or Tetapere. The coast up to Onehunga is generally formed by low perpendicular cliffs. There are (wo broad creeks of no depth, besides several smaller streams in the various bights. The points are of a soft grey level sand stone, extending in straight layers from the points to the S.W. but in some instances taking a curvelinear form. Karangahapi Bay has deep iron sand. The Papakura channel cutting through the middle of the flats is 12J miles in length, has 8 to 10 fathoms for the first three miles, and never less than 4 to within the Heads where there is 4J fathoms. The Wata Paka falls into it 4 miles up having 3 to 4 fathoms for two miles, when it becomes narrow and winding with £ a fathom to its head. The Pukaki joins two miles above this having a good boat channel. The Waiuku channel commencing from Te Hohono point opposite to Poponga, is six miles to its Heads, averages 8 fathoms, decreasing to 4 near the Heads. There is a hole of 17 fathoms at the entrance and 6 fathoms after passing the Heads in which depth there is anchorage a mile within. VesieU not drawing more than 12 feet can go up at far as tho nccdlet, 1£ miles from the portage. ' The Tuihiki, « tributary one mile within Karaka Point, ii navigable for craft drawing 6 feet water, for 2 miles. The channel into the Waiuku is along the const, and it is generally steep, from point to point. Having shown that Manakau poiiesset three channels formed by nature, of sufficient depth to allow the largest vessels to enter into the heart of the country at three equidistant point*, it is unne« cessary and would be presumptuous in me to describe a surrounding country so well known. In framing this report of the harbour, we should be doing injustice to the subject, if in proving its easy access we lost light of ihe most essential questions. Is it always so ?— and is it so at Night ? I am not prepared to recommend a vessel to run for Manukuu in a gale, for on such occasions there would be a continuous break, and leading marks might be obscured, fortunately such galei, however frequent, are not of great duration. As to entering at night I should consider the light on the extreme of Poponga as a leading mark to such perions who have become acquainted with the Port, and especially in command of a steamer for which Manukan is peculiarly eligible. When a flag-staff is established on Paratutai, vessels can be guided as at Hokianga, the dipping of the Arm would make known when a vessel is too far over either way, and when this is established vessels will not fear working out with the tide. Hi* Excellency, I am aware, ii fully prepared to give effect to any means benefitting this harbour, and as a seaman I can state I believe nothing would add to the confidence of intending visitors, more than the establishment of the signal station. From the station, One Tree Hill near Onehunga being conspicuous, might be made the medium of communicating with Auckland. Tbe reports of the levels from two different pointi of the Manukaa, as well at sections and plans, have already been delivered by me to the Colonial office. ! The intereiting and valuable levels from Waiuku to the Waiktto, i am assured are satisfactorily com* pleted, and I only remark that it appears to me a matter of consideration in forming the canal here whether it would not be done more reasonably and effectually by cutting through the morass as far as the woodi which from (I acknowledge) caiual obser vatiom would save at least half the distance, and the same water could be turned to tbii channel. A similar cut through the forest would undoubtedly be a work of great labour, but, fortunately, here it is not needed, as the course is comparatively much straighter. The clearing out of this portion of the Awaroa which endangers the navigation of canoes, and rendeis that of boats almost impracticable, could be done, I think,, by the desire of His Excellency. The impediments are trees, that were principally thrown across by the Waikato tribes to pretent the descent of the murderous E' Hongi, and have been no doubt added to by the occasionalunciermiung of trees during the freshes, U is well

known that many valuable native cargoes have been loit and damaged, in consequence of tbeie obitructiom, and I find on enquiry that th« Na« tivea only require a little well timed advice, and perbapa small aasistance to remote an obstacle that ia at the present moment impeding the trade to Waikato. If it ihonld be hereafter determined to cut the canal to the foreit, independent of the aerpentine windings of the Awaroa, until reaching the forest, it would appear to me that a swamp of moderate bretdth, about a £ of a mile west of Mr. Constable 1 ! Inn would offer a lets level than a direct line from the creek there, but npon this point I offer suggestions with de'erence, and only to open a consideration on a point probably already better determined. The survey of this harbour on a large scale, (■ix inches to a mile) was made at the request of tbe Colonists, conveyed through Lieutenant-Go* vsrnor Wynyard, and I have no hesitation in recording the names of the officers employed during part of a most unseasonable summer, which prolonged oar work. The open boats in which they and the crewi lived and slept, were absent from the ship in the channels for a fortnight at a time, but no casualty or sickness of any kind occurred. Mr. Kerr (Acting Master) and Mr. H. Kerr, were employed in the ' Maori' cutter, in sounding the outer waters. The latter officer, also with Mr. Stanley, Master's Assistant, walked and surveyed the coast lint from Kaipara Heads to Manokau. . Mr. Oke, 2nd Master, with Mr. Ellis, conducted the investigation of the Papakura and Wuiuku channels, and Messrs. Blackney and Farmer aounded and surveyed the three channels leading to Ouehunga. Mr. Blackney also accompanied me in the survey of the Waikato heads. I have also much pleasure in mentioning the zealous manner in which the work waa carried on daring my necesury absence, by Lieutenant Jones. I annex the time of high water, full and change at different points. A description of the site for signal and light stations, as well as the number and description of buoys and perches required for each channel. The position for these buoya are marked on our charts, and I will Immediately place a tracing of the entrance and Sailing directions in the Survey Office.

Relative to the lite for a signal lUtion and light house :— After examination, we find that there ii no place 10 well adapted as Paratutai for the former. Although iteep, it it sufficiently scceiiible, and can be made much easier ; from the aummit ia an exteniire view seaward in all direction!, wbich could not be obtained below. The flag-staff would be on the Apex 350 feet abore the sea, here it 80 feet by 30. Immediately below thit (but on Paratutai) there it a lite for a, dwelling, with about half an acre of ground, hating toil 3 or 4 feet deep. The only difficulty it water, which must either be tupplied by a tank, or from a atream which runa near the foot of Paratutai. By the flag ataff, a light revolving or colored, to be diitinguiihed from Natire firea, would be a guide ti the entrance at night, but cannot be available to had resielt in. But if a light wat placed on the outer extreme of Poponga, it would be alwayt eclipied by Pmtutai, when a Tetiel wat too far to the Northward, and by keeping it jait open, it it in reality the tame mark at given for steering in by day. in buoying off the channel! of Manukau, I thiuk two large buoyi »re only necetiary, became tbe mark*, with the Orwell and mid bank, forming auch decided tea wallt, are aufficient. The two outer buoyt thould be large can bnoyt, and laid down with the bett gear. I hare marked the potition. The tpit off the South head may have a small-r buoy. Thoie at the tail of the banks forming the three channeli thould be of the tame deicripiion, whereas, the buoyi for navigating the channels, need only be cask buoyt. For the Onehunga channel, to Onehunga 11, and 2 perches are required. To reach within Papakura headi, 9 are required. To reach within Waiuku headi, 3 buoy*, and 3 peaches. Tbe positions of all these will be teen from tbe chart. In laying down theie buoyt (especially the outer) the person in charge of the signal station thould bo practically acquainted with thtir potition, and any one or more of a crew stationed at Paratutai might be in the tame way made competent to pilot a veatel through any branch of the Munukau. A vessel from twenty to thirty tent thould be employed in laying down the outer buoys according to the weather, between December and March. In fine weather it would occupy but little time.

Total Number of Buoyt required. Large Can Buoya .. 2 Middle-lized ditto ♦• * Onehunga main channel 1 Cask jj and inner ditto / Buoys Papskara channel ditto 9 Waiuku channel 3 Total—2 large, 4 miJdle-tized, and 23 imall. There are alto required — For Onehunga channel 2 perche». For Waiuku 3 " Total .. .. 5 Btbon Dkuey, Commander and SurTejor. * i hare been diiappointed in obtaining the information regardiog reneti which hare gone into Maoukaa under theie circumitancei.