.
Here is a transcript of the 1840 sailing directions to the Rock and Horse Channels.
Original spellings are retained, direction is given as magnetic bearings
(variation 26° west); some fractions have been rewritten as decimals.
Page numbers, illustrations and appendices refer to the original.
See
original images.
See below for sections on Lighthouses; Lifeboats; and the Northwest Lightship.
Denham's chart (sketch for orientation, East up) of the area:
.
These channels unite in continuous order, forming a bending course
of stream, southward and then eastward, from the N.W.
Light-ship to the Rock Lighthouse. The Horse Channel is the seaward
portion, bounded on the south-western hand by East Hoyle Spit and high
sand-bank, which ranges 4.5 miles right out north-westward from Dove
Point; and, on the north-eastern hand, by the Sixfeet Flats, which
outlie the North Spit 1.5 mile N.W. by W. The Rock Channel is formed
by the main strand on the southern hand, which outlays the high-water
mark in a flattened shelf of sand, that dries out from Dove Point 1 mile
(called Dove Spit), from Leasowe Castle 0.75 of a mile (called West
Wharf), and from Wallasey Sandhills 0.5 a mile (called East Wharf); the
whole beach called Mock-beggar Wharf; and, on the northern hand, by the
continuous margin of North Spit, North Bank, and Brazil Bank, a trend of
North and steep sands that extend, laterally with the main, 5 miles
westward of the Rock Lighthouse, and may be considered
as presenting the southern side of that great triangle of sands, known
and dreaded as the 'Great Burbo Banks'. The Horse Channel terminates in
limit and water at the North Spit, beginning at 1 mile within
(S.E.1/2S.) the Lightship. It carries 9, 7, and 5 fathoms at low water,
until a 0.25 of a mile eastward of North and Dove Spits, or when the
Hoylake Lights come in one, (S.W.3/4S.) view L.
The first half-flood and last half-ebb sets fairly up and down this channel,
but after half-flood and before half-ebb it sets obliquely over North Spit for
Rock Lighthouse. The whole length of this channel is 3.5 miles, and at its
narrowest part (abreast of a nine-feet patch) is 0.33 of a mile wide. The N.W.
Spit and south-western margin of the channel is guarded by 4 red buoys,
numbered inward, and bearing the initial of the channel, H. The north-eastern
side is only intruded upon by the nine-feet patch, and there guarded by a
black and white nun-buoy, (marked H 1), known as the Buoy of the Flats,
inasmuch that the patch lies upon an eleven-feet spit, which springs 0.33 of a
mile westward of the Six-feet Flats. The Rock Channel is guarded
on the southern hand by four red buoys, numbered from
outer approach, and bearing its initial, R; and on its northern margin by
seven black buoys, alike numbered in succession, and marked R. This channel is
4.75 miles, trending E. by S. contracting so as to be a blind channel at low
water, by uniting with the main beach (at 0.25 of a mile below the Rock
Lighthouse) awash at low-water great springs, forming a bar of 0.5 a mile, in
and out, with 2 feet here and there, and called the Rock Gut. To
appearance, the Rock Channel widens at the lower, or western end, on account
of
the black and red buoys being twice the distance apart; but it is sadly
interrupted and in a choking state in that space, by reason of a
bank, called 'Beggar's Patch,' of 0.125 of a mile wide,
and stretching 1.25 mile obliquely, in line from West
Wharf to the North Spit, having as little as 5 feet upon its western part, and
admitting but 10 feet between that part and North Spit, in a passage of only
0.125 of a mile wide; whilst the passage between its eastern part and beach, abreast
of Leasowe Lighthouse, is nearly as shallow and narrow. Both
ends of this patch present a quartered black and white buoy,
marked B 1 and B 2, and it is above this buoy that the tide-stopping
anchorages of 'Leasowe Hole' and ' Wallasey Hole' still retain 3 and 4 fathoms
water.
Time was when the largest ships of Liverpool could retreat
to, or proceed from, these good holding-grounds, and
tolerably-sheltered road-steads, at
low-water springs; but at this date it is
barred up from 3/4 ebb to 1/4 flood for ships 18 feet; a sad
declension in the approaches to Liverpool, as the next anchorage, which a
sudden backing of wind upon a young flood imposes on a ship, is terribly
exposed to northerly winds, viz. the N.E. Buoy anchorage, i.e. between Dove
and North Spits. The approach to this occasional anchorage, up the Horse
Channel, is rendered of late a tortuous and baffling channel under a strong,
or very light, south-west wind, in consequence of the north-east elbow of East
Hoyle Bank having advanced to the N.E. and the North Spit Flats to the S.W.
since the line of sea lights were established to lead up in one. The
necessity, therefore, of opening them
one way, then crossing them and opening the other, is obvious, but
when to do so at night was most vague and hazardous, until I had the
satisfaction of masking the two Hoylake Lights upon
defined lines, in 1836. - [See Notice to Mariners, in Appendix]. By this
application of the breast-lights, the forward steering-lights, Leasowe and
Bidston, (both fixed bright lights, situated 2 miles apart, on the bearing of
S.E.1/4S. Bidston elevated 244 feet, and Leasowe 110, above half-tide mark,
[see special description, page 10], are subservient to easy night navigation with a
leading wind; pilots, indeed, manage to beat up to North Spit under a S.S.E.
wind, which affords a lay-up the Rock Channel. Even at night, therefore, you
have only to consider the lift of tide according to draft and tide-gauge
table, half-tide always giving you 16 feet through the Rock Gut; the lower
light at Rock at night indicating 12 feet lift, as a black ball does by day.
Your taking up anchorage, preparing for docking, or backing and filling, until tide time, must depend on circumstances. If too stormy for a pilot to come off, even in the river, (which I have known to happen,) anchor one-third towards the Cheshire (western) shore, as soon as you can, after rounding the Rock Lighthouse. If not intending to dock, proceed to the Sloyne anchorage, or, if proper, the quarantine ground, already described in page 42.
Should it be thick weather when you arrive off the N.W. Light-ship, and determine to proceed up Helbre Swash, you have a fairway course of S.1/2E. a fair setting tide from the bar, and 6 buoys to guide you, viz. H 1, red, with perch, on the larboard side of bar, denoting the N.W. Spit of East Hoyle, which divides the Horse Channel into Liverpool from the Swash; and a red and white striped buoy on the starboard or western side of bar, bearing the initial character of the 6 buoys of of this channel, HE 1. The first of these buoys bears S.E. by S.1/2S. 1 mile from the Light-ship; and the second HE 1, S. by W.1/4W. 0.75 of a mile from her. It is desirable you make and near the latter, to avoid the flood in-draught of Horse Channel, and in the first mile advance a black can-buoy, HE 1, will appear on the larboard hand, guarding the western margin of East Hoyle Bank; then, at 1.25 mile intervals, HE 2 and 3, black can-buoys, along the same margin in succession; whilst HE 2 and 3, red and white striped, lie south-westerly on the starboard hand, guarding the eastern edge of West Hoyle. The last of the red and white buoys denotes the eastern elbow, very steep-to, of West Hoyle; and the last of the black, HE 3, with perch, marks the S. W. sharp elbow of East Hoyle; whereat, the western entrance of Hoylake falls into Helbre Swash; which entrance is strongly marked on the southern hand by Helbre Islands, if such they may be called, for they dry up at their bases several feet above low-water level, upon a flat of sand that stretches a mile from the main; the outer south-western part of which is called Lime-wharf.
Helbre islands: These islets consist of three at high water, but are united upon one strand at low water, presenting a ridge of sand-stone rock, trending 1.75 mile S.S.E. and N.N.W. The outer and northern Great Helbre islet is the greatest; it is a 0.25 of a mile long by a sixteenth broad, presenting reddish sand-stone cliffs, of 40 feet height, flattened and verdant on its surface, with a telegraph at the outer quarter, and a white-faced dwelling-house on its eastern cliff. Middle Helbre is of same character, but of half the size, and separated by a rocky causeway of 0.125 of a mile. The inner islet is of mole-hill figure, of 30 yards diameter, situated 0.5 mile S.S.E. of middle isle, and called 'The Eye,' upon which the southern beacon for Helbre Swatch was erected at my suggestion, in 1834. A drainage-stream gutters down, affording a muddy dyke for flats, close along the eastern side of Great Helbre, with 6 feet at two-hours flood. The low-water rocks range out a cable's length from the cliff at north end of Helbre, with 13 feet close to, where the tide rises upon equinoctial springs 32 feet, ordinary springs 29 feet, neaps 22, with a mean centre or half-tide level of 16 feet, and flows upon full and change of the moon 37 minutes past 10 o'clock. The passing stream makes 5 knots upon springs, and 3 on neaps. The telegraph on Helbre is one of the Liverpool and Holyhead line, and is the intervening station between Bidston and Voel Nante. The island is situated in the port of Chester, but let on 21 years' lease, by the Dean and Chapter, to the Liverpool Dock Trust, who sub-let a part of it to the Trinity Board for storing duplicate buoys for the Dee, instead of their depot being at Chester, as in 1836. Helbre Swatch is also within the port of Chester, but was buoyed and beaconed by the Liverpool Dock Trust, at my suggestion, in 1835. Helbre Island may be termed the turning or terminating feature of the eastern arm of the Dee estuary, but it is the isolated point; the actual main land angle is Helbre Point; a low sand-hill elbow, forming the north-western angle of the Cheshire promontory that divides the Dee from the Mersey. This point lies 1 mile E.S.E. from Helbre Island, with a ridge of sand-stone rocks running out 0.25 mile due north of it, called the Red Stones, which mark the western limits of the port of Liverpool. From this point the high-water coast-line trends in gentle curvation E.1/4N. for 6.5 miles, to Rock Lighthouse, the whole line presenting sand-hills and sea-walls, with marshes running 2 miles within, except at the last half-mile, where the north-eastern shoulder of Wallasey, now called 'New Brighton,' and its red and yellow sand-stone cliffs, present remarkable features, and serve to mark that northeastern angle of Cheshire as Grange Hill and Mill do the north-western; though Grange does not rise nearer Helbre Point than 1.25 mile S.S.E. of it, but its relative altitude, with the half-tide mark, being 173 feet, commands useful attention for identity of Kirby Church, for instance, on its western slope, when working in the bay.
An additional buoyage and beaconage was laid by me in 1835, when adding 18 buoys to the Liverpool navigation. Two hours' flood will give you 10 feet at the eastern entrance, and 14 at the western. It should be observed, that the first half-flood sets in at both ends of Hoylake, meeting in the centre, i. e. off the lighthouses; and after half-flood the chief set is westward until low water. No leading mark presents itself for leading right in, but buoys are placed at the elbows. The western entrance out of Helbre Swash is assisted (if buoys are adrift) by bringing Bidston Lighthouse in one with Upper Hoylake Lighthouse, (E. by S.3/4 S.) which leads obliquely over the bar; and you must edge northward when your water shoals. On this track you will have left 2 black buoys, HE 3, with perch, and L 4, black, upon your northern hand; a red buoy, L 3, will then appear 0.33 of a mile further eastward, which guards the main beach, as the others do the S.W. elbow of East Hoyle; you must pass the red buoy close to the northward, and steer for lower lighthouse, E. by S.1/4S. until you deepen a fathom, or the large hotel is abreast of you, and closing with Kirby Church, S.1/2W. when steer east, or for the craft or mooring-buoys, a 0.25 of a mile, and choose your berth for best water with either of the lighthouses on with Grange Mill, dropping your anchor as close to Hoyle Bank as possible, which you will see, except at high-water springs. With that bank as a break-water, you have only to veer cable on the flood, and heave it in upon the ebb, and you will ride out any gale, retaining 3 fathoms water under you at low-water springs; but take care to have a kedge to the southward, in case of shift of wind to that quarter trailing you on the steep edge of Hoyle Bank upon the fall of tide. If indifferent about taking the ground, you will have soft flat layer upon the main, without any sea at half-ebb. A guide is afforded at twilight, or moonlight nights, to the deepest water of the lake, by bringing Point of Air Light on with north extreme of Helbre Island, and will ensure your being clear of Red Stones. The actual lake may now be said to exist only from the hotel to the parsonage, i.e. two-thirds of a mile, the rest of the 3 miles being shallows each way. To come into the lake from the eastward, you will find 10 feet at half-tide, directly over Dove Spit from the Rock Channel, by bringing Helbre Telegraph W. by S. until up to Jackson's Buoy, marked L 1, and red, lying upon south-eastern angle of East Hoyle, leaving it on the starboard hand, and steering S.W. by W.3/4W. up to the next red buoy, L 2, 0.75 of a mile advanced, when the Hoylake Lighthouses will come in one; after which, leaving it on your northern hand also, you will take up your anchorage as before.
If you are after half-tide on the ebb, or before it on the flood, you must bring the two Dove Beacons in one, (bearing S. by E.) taking care that you are northward of Hoylake line of lights before bringing the Dove Marks in one, whether you be running in from the Horse Channel or Rock Channel; those beacons will lead you to Jackson's Buoy, from whence haul S.W. by W.3/4W. as before. On leaving Hoylake you will be guided by wind and the place bound, as to which direction you take out. The chief importance of Hoylake now is, affording shelter to pilot-boats - a life-boat station - to passing flats and a short passage for steamers to Wales - and is of local importance to a fleet of trawlers. Vessels of burthen can only look to it according to exigency and last resource.
F1: Not only is the Helbre Swatch baneful to the navigation
into Liverpool as respects the twisting of Horse Channel, but by disgorging so
vast a bulk of the Dee-scour into that part of the bay where the first of each
flood takes up suspended matter, and trails it over the Burbo and North Banks.
F2: Under
such circumstances, the Marine Surveyor should not hesitate as to the
alternative: a pause, beyond certain extent, in the exercise of moral courage,
may jeopardise the vast concerns of a confiding community beyond redemption,
and compromise his own judgment and reputation: open demand for operative
means should take place of unavailing supplication. The crisis may require his
retiring, but the designed work will be forced into realization at any rate;
when honour and duty will be satisfied.
Lighthouses:
Lifeboats: The Life boats are stationed at Point of
Air, at Hoylake, at Formby Point and at Magazines, just within the Rock
Lighthouse; and now that a Lighthouse is on Crosby Land, I do hope a Telegraph
there will be conceded. Bidston station may take up its signals, though unable to
do so from Formby Lighthouse during the last four years' necessities of the
northern approaches.
Northwest Lightship:
It will appear from this figure of the bay that
the Light-ship, not only lies in the actual fairway ESE from Point Lynas, but
occupies a safe offing position in the bay, being 1 mile from the outer sand
heads, East and West Hoyle Banks, where they form the Horse Channel into
Liverpool, and the Helbre Swash into the Dee or Hoylake. She lies in 7 fathoms
at low water springs and, from her being the outer (north western) beacon
object of the port, is called the North-West Light-Ship; presenting a
bluff-built hull of about 130 tons, with a short bowsprit and painted black:
she is three masted carrying at the main a large black ball by day, and
exhibits three brilliant bright lights (between sunset and sunrise) from
lanterns fitted round the masts, with 8 lamps and reflectors in each appearing
in the order of fore, main and mizen tops, respectively elevated 32, 40, and 26
feet above her water line, so that they cannot blend as one light, except at a
considerable distance or in hazy weather, to provide for which and to
distinguish her from all other lights in the region, a blue light of 3 minutes
duration is burnt on board of her every two hours of darkness according to the
seasons and mean time at Liverpool: thus during November, December, January
and February, 6, 8, 10, 12 pm, 2, 4 and 6 am; March, April, September and
October, 8, 10, 12 pm, 2, and 4 am; May, June, July and August, 10, 12 pm and
2 am. See copy of Advertisement of April 30 1836 in Appendix. To allow for
difference of time at ship, a look out should be kept, in the anticipated
bearing, 5 minutes before the respective hours. These blue lights, being
elevated on a pole, can be seen in the horizon as soon as her mizen lantern
rises to view, which is at 10 miles distance. During fog, this vessel rings
her bell and sounds a gong alternately, and, to give a chance of being peered
out under a dense haze, the mizen lantern is lowered level with the gunwale.
It will also be useful to know, by those who possess the Liverpool code of
signals, that this vessel can take them up and pass them on in telegraphic
order to Helbre semaphore. I would suggest that steamers running up in a fog,
heave to occasionally, to catch the sound of the gong, uninterrupted by the
paddle noise, and would observe, to those who may be hovering in her region
waiting for water through the Rock Channel, that it is desirable they keep two
cables off the Light ship, or they may very unthinkingly obscure her lights by
their smoke and steam-escape. To vessels that may be arriving in the bay about
the usual time of the Government Mail-boats, it will be useful to know that
the Light-ship repeats a gun for every one supposed to be fired in hazy
weather by those packets. This Floating-Light lies on the fairway-course into
the Horse Channel, (S.E.1/2S), and into Helbre Swash, (S.1/2E). Her best
adapted site at this date is intersected by the following cross-marks,
bearings, and distances, viz.
Bidston Lighthouse - its apparent breadth open eastward of
Leasowe Lighthouse, S.E.1/2S.
She lies in 7 fathoms
(fine sand) at low-water springs, with 9 fathoms between her and the entrance
of Horse Channel and Helbre Swash; whilst the soundings shoal up
from 10 fathoms (fine sand) in her western horizon, 10 miles off,
and at that distance to the northward 10 fathoms (sand and mud) will likewise
be found; but vessels approaching cautiously by the lead from that direction,
should expect to get soundings on a five-fathom ridge, of 0.5 a mile width,
when 2.5 miles north of the Light-ship, deepening again to 7.5 fathoms between
her and the ridge. The ship's position is upon the western extreme of the
seven-fathom under-shelf, which trails from the Newcome Knowl, and on the eastern margin
of the Horse Channel stream, where the EBB-tide sets past her
W. by S. during the first hour, W. by N. the second hour, and N.W. the last 4
hours: the FLOOD-tide sets by her the whole 6 hours S.E. by E. being rather
towards the Six-feet Flats than the Horse Channel fairway. Each tide turns as
it ceases to rise and fall, (which is 3/4 of an hour earlier than at the
docks), but no perceptible difference in flood and ebb velocity exists. From the
following table, however, the mariner will gather at a glance the rate of his
hourly drift in calm hazy weather, upon springs and neaps.
Progressive velocity of stream at NW Lightship.
Rock Lighthouse (Liverpool Dock Trust)
situated at the mouth of the Mersey a cable's length within the low water
extremity of rocks upon which it is based, 12 feet
above LW level at a quarter of a mile outside HW mark. An isolated Fort
constructed of red sandstone stands midway between it and the elbow of
Sandhills recently called New Brighton Point. This point forms the north
eastern elbow of the north promontory of Cheshire, where part of the Mersey
still turns at right angles westward into Liverpool Bay, endeavouring to keep
open the Rock Channel. The Lighthouse is not easily distinguished amongst the
passing vessels and numerous straggling land objects on the Liverpool side, the
eye, however, will be assisted by reference to the views in Appendix, and bearing
in mind that it stands at the very throat angle of Liverpool Bay. The building
presents a beautifully proportioned Eddystone or bell-shaped tower of a lime
stone greyish colour, surrounded by the tide from two hours flood till four
hours ebb. Its lantern is elevated 77 feet above half tide level commanding a
10.5 mile range of horizon, but visible 14 from the deck of a ship. Its light is
remarkably good and well distinguished from all others in this bay or in the
Irish Sea being of intermittent colours as well as revolving: its order of
showing is two bright faces and one red in uniform gradual succession; the
refulgence of each being at intervals of one minute. A momentary obscuration of
light occurs at like intervals; the length of its darkness increases as you
distance it.
In 1835, I arranged tidal signals for night and day guidance at
this Lighthouse, and subsequently caused Fog Bells to be rung in succession
towards the Rock Crosby and Mersey Channels. The tide signals are thus: when
the tide has risen so as to produce 12 feet over Rock Gut Bar, a fixed bright
light is exhibited from a lower chamber half way down the building, down the
Rock Channel and up the Mersey until 12 feet water ceases on the bar. A black
ball indicates the same by day, when hoisted above the balcony. The Lighthouse
bears from NW Light ship SE by E 1/2E 8 miles, from Leasowe Lighthouse E 1/4N
3.25 miles, from Formby Floating Light S by E 1/2 E 6.25 miles, and from north
end of Docks N by W 1/2 W 2 miles. I had the satisfaction of improving the
brilliancy of the red light, at the same time as lessening trouble and
expense, by adopting red cylinders instead of red shields. The mariner
desiring life boat assistance will be relieved in his suspense on perceiving a
blue flag hoisted at this Lighthouse, in token of assistance preparing. The
thanks I have received for this arrangement alone, afford a vivid proof of how
the slightest anticipation on shore can relieve the helpless afloat.
Bidston Lighthouse (Liverpool Dock Trust) a dark stone
coloured octagonal tower situated upon the ridge of high land which rises from
Wallasey Pool and Bidston Marsh, trending 1.25 miles SSW upon the promontory of
Cheshire which divides the Dee and Mersey, and helping the eye to distinguish
the first stretching of the western arm of Liverpool Bay. The shoulder of this
hill (known as Bidston Hill), upon which the Lighthouse stands, is situated 1.25 mile
in-land, a dark looking wind mill stands on the same ridge 1/3 of a mile SSW. The
Lighthouse lantern is elevated 244 feet above half tide level, permitting a
range of 17.5 miles or of being distinguished 21 miles from a ship's deck; it
sends forth a fixed bright light in fullest refulgence north westward right
over Leasowe Light, two miles seaward of it in conjunction, affording an active
transit of lights for navigating the Horse Channel. Bidston Light is masked for
local inshore effect upon a NNE line, i.e. indicating when you are abreast of the
East Wharf Buoy in Rock Channel.
Leasowe Lighthouse (Liverpool Dock Trust) a
conical white tower situated near the high water mark, 2 miles seaward NW 1/2N of
Bidston Lighthouse and 3.5 miles westward of Rock Light. It exhibits a fixed
bright light from a lantern, elevated 110 feet above half tide level, throwing
its focal strength to the NW over the Light ship, commanding a 12 mile horizon
but visible 16 miles from the deck of a ship. Its only desired object was in
conjunction with Bidston to act as a line of sea lights for the Horse Channel,
until 1837, when I masked it as well as Bidston for checking course in the Rock
Channel, so that when Leasowe Light disappears in the Rock Channel (bearing SW)
you are abreast of the West Wharf Buoy.
Hoylake Lighthouses (Liverpool Dock Trust) Two white buildings
situated obliquely to the line of Hoylake coast line 3/4 of a mile eastward of
Helbre Point at the northern extremity of Cheshire. The one nearest high water
mark is a rounded gable of a dwelling house, with its lantern 47 feet above
half tide level, ranging 7.5 miles. The inner and upper Lighthouse is a sugar
loaf tower, with lantern 72 feet elevated, and ranges 9.5 miles. The buildings
lie SW 3/4 S 1/5th of a mile apart. They throw their best light bright and
fixed directly in their line NE 3/4 N, forming a leading mark clear of Dove
Spit, and checking the Bidston and Leasowe line for turning up Rock Channel,
or anchoring. The lower light is so masked as to denote when you are abreast
of NW Spit of East Hoyle, S by E 1/2 E, upon line of the Sea-lights (Bidston
and Leasowe so called). And the upper light is so masked as to indicate when
you are due north of it, and checks the sea-lights course half a mile NW of
Buoy of Flats in Horse Channel. These are the southwestern lights in Liverpool
Bay.
Point of Air Lighthouse.
Crosby Lighthouse: a wooden
structure erected by the Dock Committee of Liverpool and lighted October 10th
1839. It acts upon the line of direction in conjunction with a floating light
pointed out by me in especial report to that Committee, dated October 4 1838
urging the necessity of, and my undertaking to, produce a fresh entrance into
the New Channel, and for superseding the Formby Light as no longer applicable
to that channel. The new fabric presents to the eye from seaward a flat faced
shaft in width one fifth of its height and shored up on either side. It
exhibits a red fixed light at an altitude of 81 feet
above HW level, 96 above half tide level, or 111 above LW level,
ranging to an average horizon in the western aspect which permits its being
picked up 16 miles off from the deck of a ship, but it is limited for local
purposes to a 95 degrees embrace of aspect viz from SW by W 3/4W to N by W 3/4 W. It
stands at the HW margin of Sandhills which form the rounding trend of coast
line between the Liverpool Docks and Formby Point, bearing from the recently
lighted tower - Formby SE mark - SSW 1.5 miles. Crosby Church (dark square tower) and
White Mill lie at equal breast-distance Southward, as the SE mark does
Northward, affording well known objects for identifying the low-stretching
eastern arm of Liverpool Bay when, approaching from the Northward or N Westward,
in the event of Crosby Lighthouse being prostrated by fire or gale. Its site is
situated in latitude 53° 30' 48" N longitude 3° 3' 53" W.
The Helbre Swash Marks - their apparent breadth open eastward, S.1/4E.
Crosby Lighthouse, E.1/2S distant 9 miles.
Rock Lighthouse, S.E. by E.1/2E distant 8.75 miles.
Leasowe Lighthouse, S.E.1/2S distant 6.33 miles.
Helbre Telegraph, S.1/4 distant 4.75 miles.
Point of Air Lighthouse, S.W.3/4S distant 5.75 miles.
| Time | Rate of Springs | Rate of Neaps | Hour | knots | knots |
|---|---|---|
| 1st | 0.75 | 0.25 |
| 2nd | 1.5 | 1.0 |
| 3rd | 2.75 | 1.5 |
| 4th | 2.0 | 1.0 |
| 5th | 1.0 | 0.5 |
| 6th | 0.8 | 0.25 |
And thence, the extent of his offing with reference to the time he passed the Light-ship on the ebb, or suggesting when he should anchor with reference to his draft of water on the flood; observing that the whole amount of spring-tide drift in the vicinity of the Light-ship is not more than 8.5 miles, and a neap-tide drift 4.5 miles; therefore, as the nearest shallow (Six-feet Flats) in the tide's-course is 4 miles from the Light-ship, it would be half-flood (15 feet rise) before he drifted there, which would yield thereon 21 feet water; the fourth hour drift would bring him to the North-bank Spit, with 12 feet over it, but on neaps it would be high water before he could drift to that spit at all. It is therefore also clear, that, if a ship is becalmed at half-ebb abreast of the Light-ship, she will have attained an offing of her on springs of 4.5 miles, and on neaps 2.5 miles, from whence the whole flood cannot drift her upon a shallow.