Board of Trade regulations concerning lights, fog signals, steering and sailing rules, pilot signals, etc.—Custom House clearance on returning from a foreign port—Explanation of the terms used in giving steering directions, etc.
Any one who ventures to take charge of even a small yacht should be familiar with the Board of Trade regulations for preventing collisions at sea, and not only with those rules which have been laid down for his own guidance, but with those applying specially to steamers, to fishing boats or other craft differing from his own, that he may recognize their manœuvres when he comes across them, and thus be able to avoid collision with them.
We will now quote the Board of Trade regulations, making such comments and explanations as we think will be useful.
Art. 1.—In the following rules every steam ship which is under sail and not under steam is to be considered a sailing ship; and every steam ship which is under steam, whether under sail or not, is to be considered a ship under steam.
The following are the Rules concerning Lights:—
Art. 2.—The lights mentioned in the following Articles, numbered 3, 4, 5, 6, 7, 8, 9, 10, and 11, and no others, shall be carried in all weathers, from sunset to sunrise.
Art. 3.—A seagoing steam ship when under way shall carry—
(a) On or in front of the foremast, at a height above the hull of not less than 20 feet, and if the breadth of the ship exceeds 20 feet, then at a height above the hull not less than such breadth, a bright white light, so constructed as to show an uniform and unbroken light over an arc of the horizon of 20 points of the compass; so fixed as to throw the light 10 points on each side of the ship, viz., from right ahead to two points abaft the beam on either side, and of such a character as to be visible on a dark night, with a clear atmosphere, at a distance of at least five miles.
(b) On the starboard side, a green light so constructed as to show an uniform and unbroken light over an arc of the horizon of 10 points of the compass; so fixed as to throw the light from right ahead to two points abaft the beam on the starboard side, and of such a character as to be visible on a dark night, with a clear atmosphere, at a distance of at least two miles.
(c) On the port side, a red light, so constructed as to show an uniform and unbroken light over an arc of the horizon of 10 points of the compass; so fixed as to throw the light from right ahead to two points abaft the beam on the port side; and of such a character as to be visible on a dark night, with a clear atmosphere, at a distance of at least two miles.
(d) The said green and red side lights shall be fitted with inboard screens projecting at least three feet forward from the light, so as to prevent these lights from being seen across the bow.
Art. 4.—A steam ship, when towing another ship, shall, in addition to her side lights, carry two bright white lights in a vertical line one over the other, not less than three feet apart, so as to distinguish her from other steam ships. Each of these lights shall be of the same construction and character, and shall be carried in the same position as the white light which other steam ships are required to carry.
Art. 5.—
(a) A ship, whether a steam ship or a sailing ship, which from any accident is not under command, shall at night carry, in the same position as the white light which steam ships are required to carry, and, if a steam ship, in place of that light, three red lights in globular lanterns, each not less than 10 inches in diameter, in a vertical line one over the other, not less than three feet apart, and of such a character as to be visible on a dark night, with a clear atmosphere, at a distance of at least two miles; and shall by day carry, in a vertical line one over the other, not less than three feet apart, in front of but not lower than her foremast head, three black balls or shapes, each two feet in diameter.
(b) A ship, whether a steam ship or a sailing ship employed in laying or in picking up a telegraph cable, shall at night carry in the same position as the white light which steam ships are required to carry, and, if a steam ship, in place of that light, three lights in globular lanterns, each not less than 10 inches in diameter, in a vertical line over one another, not less than six feet apart: the highest and lowest of these lights shall be red, and the middle light shall be white, and they shall be of such a character that the red lights shall be visible at the same distance as the white light. By day she shall carry in a vertical line one over the other not less than six feet apart, in front of but not lower than her foremast head, three shapes not less than two feet in diameter, of which the top and bottom shall be globular in shape and red in colour, and the middle one diamond in shape and white.
(c) The ships referred to in this Article, when not making any way through the water, shall not carry the side lights, but when making way shall carry them.
(d) The lights and shapes required to be shown by this Article are to be taken by other ships as signals that the ship showing them is not under command, and therefore cannot get out of the way. The signals to be made by ships in distress and requiring assistance are contained in Article 27.
Art. 6.—A sailing ship under way, or being towed, shall carry the same lights as are provided by Article 3, for a steam ship under way, with the exception of the white light, which she shall never carry.
Art. 7.—Whenever, as in the case of small vessels during bad weather, the green and red side lights cannot be fixed, these lights shall be kept on deck, on their respective sides of the vessel, ready for use; and shall, on the approach of or to other vessels, be exhibited on their respective sides in sufficient time to prevent collision, in such manner as to make them most visible, and so that the green light shall not be seen on the port side nor the red light on the starboard side.
To make the use of these portable lights more certain and easy, the lanterns containing them shall each be painted outside with the colour of the light they respectively contain, and shall be provided with proper screens.
Art. 8.—A ship, whether a steam ship or a sailing ship, when at anchor, shall carry, where it can best be seen, but at a height not exceeding 20 feet above the hull, a white light in a globular lantern, of not less than 8 inches in diameter, and so constructed as to show a clear uniform and unbroken light visible all round the horizon, at a distance of at least one mile.
Art. 9.—A pilot vessel, when engaged on her station on pilotage duty, shall not carry the lights required for other vessels, but shall carry a white light at the masthead, visible all round the horizon, and shall also exhibit a flare-up light or flare-up lights at short intervals which shall never exceed fifteen minutes.
A pilot vessel, when not engaged on her station on pilotage duty, shall carry lights similar to those of other ships.
Art. 10.—Open boats and fishing vessels of less than 20 tons net registered tonnage, when under way and when not having their nets, trawls, dredges, or lines in the water, shall not be obliged to carry the coloured side lights; but every such boat and vessel shall in lieu thereof have ready at hand a lantern with a green glass on the one side and a red glass on the other side, and on approaching to or being approached by another vessel, such lantern shall be exhibited in sufficient time to prevent collision, so that the green light shall not be seen on the port side nor the red light on the starboard side.
The following portion of this article applies only to fishing vessels and boats when in the seas off the coast of Europe lying north of Cape Finisterre:—
(a) All fishing vessels and fishing boats of 20 tons net registered tonnage, or upwards, when under way and when not required by the following regulations in this Article to carry and show the lights therein named, shall carry and show the same lights as other vessels under way.
(b) All vessels when engaged in fishing with drift nets shall exhibit two white lights from any part of the vessel where they can be best seen. Such lights shall be placed so that the vertical distance between them shall be not less than six feet, and not more than 10 feet; and so that the horizontal distance between them measured in a line with the keel of the vessel shall not be less than five feet and not more than 10 feet. The lower of these two lights shall be the more forward, and both of them shall be of such a character, and contained in lanterns of such construction as to show all round the horizon, on a dark night, with a clear atmosphere, for a distance of not less than three miles.
(c) A vessel employed in line fishing with her lines out shall carry the same lights as a vessel when engaged in fishing with drift nets.
(d) If a vessel when fishing becomes stationary in consequence of her gear getting fast to a rock or other obstruction, she shall show the light and make the fog signal for a vessel at anchor.
(e) Fishing vessels and open boats may at any time use a flare-up in addition to the lights which they are by this Article required to carry and show. All flare-up lights exhibited by a vessel when trawling, dredging, or fishing with any kind of drag net, shall be shown at the after part of the vessel, excepting that, if the vessel is hanging by the stern to her trawl, dredge, or drag net, they shall be exhibited from the bow.
(f) Every fishing vessel and every open boat when at anchor between sunset and sunrise shall exhibit a white light visible all round the horizon at a distance of at least one mile.
(g) In fog, mist, or falling snow, a drift net vessel attached to her nets and a vessel when trawling, dredging, or fishing with any kind of drag net, and a vessel employed in line fishing with her lines out, shall at intervals of not more than two minutes make a blast with her fog horn and ring her bell alternately.
Art. 11.—A ship which is being overtaken by another shall show from her stern to such last-mentioned ship a white light or a flare-up light.
It follows from the above regulations that the following lights must be carried on board a small sailing boat—A white riding light, a green starboard light, a red port light, and a bull’s-eye lantern, with which last one can carry out the instructions conveyed in Article 11.
A very convenient lantern is now sold by the yachting outfitters, which not only combines in itself the port and starboard lights, as permitted by Article 10; but on the removal of a slide serves as a riding-light as well.
Small yachts are generally provided with lanterns of smaller size and lesser illuminating power than those enjoined in the regulations; but it is best to comply with these rules if possible, so that one can have the right on one’s side in case of a collision. It often happens again that small lights burn in an unsatisfactory manner, and frequently go out. A riding light that does this is a great nuisance, and spoils one’s night’s rest when one is brought up in a crowded thoroughfare.
We prefer lanterns that burn paraffin, for sea work; if colza is used, some camphor should be dissolved in it: this increases the illuminating power, and in our opinion the light is not so likely to go out when this is done.
The following rules relate to Fog Signals. It will be observed that the old-fashioned fog horn which is sounded with the mouth is not recognized by the present regulations. It is, however, still generally used on small craft, and will certainly make more noise than some of the mechanical fog horns:—
Art. 12.—A steam ship shall be provided with a steam whistle or other efficient steam sound signal, so placed that the sound may not be intercepted by any obstructions, and with an efficient fog horn to be sounded by a bellows or other mechanical means, and also with an efficient bell. A sailing ship shall be provided with a similar fog horn and bell.
In fog, mist, or falling snow, whether by day or night, the signals described in this Article shall be used as follows; that is to say—
(a) A steam ship under way shall make with her steam whistle, or other steam sound signal, at intervals of not more than two minutes, a prolonged blast.
(b) A sailing ship under way shall make with her fog horn, at intervals of not more than two minutes, when on the starboard tack one blast, when on the port tack two blasts in succession, and when with the wind abaft the beam three blasts in succession.
(c) A steam ship and a sailing ship, when not under way, shall, at intervals of not more than two minutes, ring the bell.
Art. 13.—Every ship, whether a sailing ship or steam ship, shall in fog, mist, or falling snow, go at a moderate speed.
Next come the articles relating to the Rules of Steering and Sailing.
In applying these the novice must never forget that when he stands on his deck and looks forward, the port side of his vessel is on his left, the starboard side on his right. When a vessel is on the port tack the wind is blowing from the port or left side of him; when she is on the starboard tack from the starboard or right side.
Let him also remember that though he should observe these rules as closely as possible, Article 23 affords a fine loophole for the huge and clumsy steamers that crowd the Thames and other rivers. It is a well-known fact that big steamers will not get out of the way of small sailing craft, even when they can do so without difficulty, and the little boat is expected to get out of their way.
The moral of this is:—Keep out of the way of the big steamers, not by getting flurried and altering your course at the last moment, against all the rules of the road, and so putting yourself in the wrong if there is a collision, but by altering your course and showing them your intentions some time before they are near you.
Art. 14.—When two sailing ships are approaching one another, so as to involve risk of collision, one of them shall keep out of the way of the other, as follows, viz.:—
(a) A ship which is running free shall keep out of the way of a ship which is close hauled.
(b) A ship which is close hauled on the port tack shall keep out of the way of a ship which is close hauled on the starboard tack.
(c) When both are running free with the wind on different sides, the ship which has the wind on the port side shall keep out of the way of the other.
(d) When both are running free with the wind on the same side, the ship which is to windward shall keep out of the way of the ship which is to leeward.
(e) A ship which has the wind aft shall keep out of the way of the other ship.
Art. 15.—If two ships under steam are meeting end on, or nearly end on, so as to involve risk of collision, each shall alter her course to starboard, so that each may pass on the port side of the other.
This Article only applies to cases where ships are meeting end on, or nearly end on in such a manner as to involve risk of collision, and does not apply to two ships which must, if both keep on their respective courses, pass clear of each other.
The only cases to which it does apply are, when each of the two ships is end on, or nearly end on, to the other; in other words, to cases in which, by day, each ship sees the masts of the other in a line, or nearly in a line, with her own; and by night, to cases in which each ship is in such a position as to see both the side lights of the other.
It does not apply, by day, to cases in which a ship sees another ahead crossing her own course; or by night, to cases where the red light of one ship is opposed to the red light of the other, or where the green, light of one ship is opposed to the green light of the other, or where a red light without a green light, or a green light without a red light, is seen ahead, or where both green and red lights are seen anywhere but ahead.
Art. 16.—If two ships under steam are crossing, so as to involve risk of collision, the ship which has the other on her own starboard side shall keep out of the way of the other.
Art. 17.—If two ships, one of which is a sailing ship and the other a steam ship, are proceeding in such directions as to involve risk of collision, the steam ship shall keep out of the way of the sailing ship.
Art. 18.—Every steamship, when approaching another ship, so as to involve risk of collision, shall slacken her speed or stop and reverse, if necessary.
Art. 19.—In taking any course authorized or required by these Regulations, a steam ship under way may indicate that course to any other ship which she has in sight by the following signals on her steam whistle, viz.:—
One short blast to mean “I am directing my course to starboard.”
Two short blasts to mean “I am directing my course to port.”
Three short blasts to mean “I am going full speed astern.”
The use of these signals is optional; but if they are used, the course of the ship must be in accordance with the signal made.
Art. 20.—Notwithstanding anything contained in any preceding Article, every ship, whether a sailing ship or a steam ship, overtaking any other, shall keep out of the way of the overtaken ship.
Art. 21.—In narrow channels every steam ship shall, when it is safe and practicable, keep to that side of the fairway or mid-channel which lies on the starboard side of such ship.
Art. 22.—Where, by the above rules, one of two ships is to keep out of the way, the other shall keep her course.
Art. 23.—In obeying and construing these rules, due regard shall be had to all dangers of navigation; and to any special circumstances which may render a departure from the above rules necessary in order to avoid immediate danger.
Art. 24.—Nothing in these rules shall exonerate any ship, or the owner, or master, or crew thereof, from the consequences of any neglect to carry lights or signals, or of any neglect to keep a proper look-out, or of the neglect of any precaution which may be required by the ordinary practice of seamen, or by the special circumstances of the case.
Art. 25.—Nothing in these rules shall interfere with the operation of a special rule, duly made by local authority, relative to the navigation of any harbour, river, or inland navigation.
Art. 26.—Nothing in these rules shall interfere with the operation of any special rules made by the Government of any nation with respect to additional station and signal lights for two or more ships of war, or for ships sailing under convoy.
The next article relates to Signals of Distress:—
Art. 27.—When a ship is in distress and requires assistance from other ships or from the shore, the following shall be the signals to be used or displayed by her, either together or separately, that is to say:—
In the daytime—
1. A gun fired at intervals of about a minute.
2. The International Code signal of distress indicated by N.C.
3. The distant signal, consisting of a square flag, having either above or below it a ball, or anything resembling a ball.
At night—
1. A gun fired at intervals of about a minute.
2. Flames on the ship (as from a burning tar barrel, oil barrel, etc.).
3. Rockets or shells, throwing stars of any colour or description, fired one at a time at short intervals.
The flags of the International Code of signals should be carried on every cruising yacht, they will often be found of service. For a small yacht, flags 2 feet by 1½ will suffice. These, together with the Code Signal Book, will cost a little over two pounds. The book explains the use of the flags, which is easily acquired.
While we are dealing with the Board of Trade Regulations, it may be well to remind the amateur skipper that should he call at any foreign port, he is bound under a heavy penalty to report himself to the Customs Officers at the first British port he enters on his return home; and that if, after sailing from some foreign port, he is ascending the Thames, he must bring up opposite the Customs landing-stage at Gravesend, that the authorities may clear him, and until he has obtained his clearance he must fly the national ensign by day and carry a light under his bowsprit by night.
The yachtsman will occasionally require the services of a pilot or local fisherman to show him the way into some difficult harbour, and it is probable that he will be considerably confused by the steering directions given to him by his guide, and put the helm to port when he should have put it to starboard or vice versâ. And this is not to be wondered at; for even professionals are often puzzled by the somewhat uncertain signification of the terms now in use.
First as to the orders most frequently given at sea—“Port!” and “Starboard!” Surely there can be no vagueness about their meaning; but every sailor will tell you that there is a vagueness, and one that is no doubt responsible for many accidents.
When an English pilot cries out “Port!” or what comes to the same thing, holds his hand out to port, he does not wish the vessel’s head to be turned to port, but that the helm or tiller be put to port, this action of course turning the vessel’s head in a starboard direction.
Wheels are now generally used in the place of tillers on all craft of any size. Now a wheel works in a contrary direction to a tiller, that is, a wheel turning to port turns the vessel’s head to port. In this case, when an English pilot cries out “Port!” he means that the wheel rudder and head of the vessel are all to be turned to starboard.
If this rule—viz., that on every occasion on which the orders “port” or “starboard” are given, the vessel’s head must be turned in the opposite direction—prevailed everywhere, all would accustom themselves to it and there would not be much confusion. But, if we cross the Channel to France, or visit some other continental countries, we find the pilots always speak of the vessel’s head and not of the helm when they give an order. In France, “Port!” does not signify “Port your helm!” but “Turn your vessel’s head to port,” which is the reverse of what a British pilot would mean when giving the same order.
There are other methods of giving orders to the man at the tiller which must be thoroughly understood by every amateur. The author has seen a somewhat experienced yachtsman puzzled when a boatman, who had come on board to pilot us, cried out, “Bear up!” at the same time holding his hand to windward.
Had he cried out “Bear away!” the yachtsman would have understood that the order applied to the head of the vessel—that the vessel was to be steered away from the wind. But “Bear up!” and the hand pointing to windward confused him, and he steered to windward or luffed.
Now these two orders mean exactly the same; but whereas “Bear away!” applies to the vessel’s head, “Bear up!” applies to the vessel’s helm or tiller which must be pushed up to windward. So, too, the pilot’s hand, pointing to windward, signified, “Put the helm in that direction,” and not “Turn the vessel in that direction.”
In the table below the orders in general use are defined:—
1. “Port” signifies “Turn the helm or tiller to port.”
2. “Starboard” signifies “Turn the helm or tiller to starboard.”
3. “Luff” signifies “Turn the vessel’s head to windward.”
4. “Bear away” signifies “Turn the vessel’s head away from the wind.”
5. “Bear up” signifies “Turn the helm or tiller to windward.”
6. “Put the helm down” signifies “Turn the helm or tiller away from the wind.”
7. “Put the helm up” signifies “Turn the helm or tiller to windward.”
It will be seen that 4, 5, and 7 are various methods of giving the same order, while 3 and 6 are the same.
The following regulations relate to Pilot Signals:—
In the Daytime.—The following signals, numbered 1 and 2, when used or displayed together or separately, shall be deemed to be signals for a pilot in the daytime:—
1. To be hoisted at the fore, the jack or other national colour usually worn by merchant ships, having round it a white border, one-fifth of the breadth of the flag; or
2. The international code pilotage signal, indicated by P.T.[*]
[*] This is a square blue flag, having in its centre a white square, hoisted over a flag of a similar shape—the latter showing three vertical bars, coloured red, white, and blue.
At Night.—The following signals, numbered 1 and 2, when used or displayed together or separately, shall be deemed to be signals for a pilot at night:—
1. The pyrotechnic light, commonly known as a blue light, every fifteen minutes, or
2. A bright white light, flashed or shown at short or frequent intervals, just above the bulwarks, for about a minute at a time.
And “Any master of a vessel who uses or displays, or causes or permits any person under his authority to use or display, any of the said signals for any other purpose than that of summoning a pilot, or uses, or causes, or permits any person under his authority to use any other signal for a pilot, shall incur a penalty not exceeding twenty pounds.”
Mercator’s chart—The mariner’s compass—The spirit compass—Variation—Deviation—The log ship and line—The lead line.
As soon as the amateur leaves the bay or river with whose features he is well acquainted and ventures to take his vessel along a coast unknown to him, he must provide himself with the necessary instruments for finding his way and make himself familiar with their use.
As the management of large yachts is not within the scope of this book, it will be unnecessary to treat here of navigation properly so called, that is, the art of guiding a vessel across broad seas, out of sight of land, by observation of the sun
and stars and by dead reckoning. But we may remark that an educated man will find no difficulty in rapidly acquiring the art of navigation if he wishes to do so. It is the seamanship that will give him trouble; for to acquire that a long apprenticeship and considerable natural capacity are necessary.
For coasting purposes and for crossing narrow seas such as the Channel, and the North Sea, and even for a voyage to the Baltic, sextants, chronometers, and other instruments of navigation proper are not required, and the following is a complete list of all that is needed for the purpose of finding one’s way. 1. The necessary charts. 2. A mariner’s compass. 3. A parallel rule. 4. A pair of compasses or dividers. 5. A log ship and line. 6. A hand-lead and line. 7. One of the small nautical almanacs which give the tide tables for the principal harbours of Europe. Pearson’s almanac, which only costs sixpence, is one of the best of these and, in addition to the tides, imparts a great deal of useful information.
Charts.—Whatever method is employed for representing a portion of a globe on a plane surface, the result can only be approximately correct. Charts are drawn on what is known as Mercator’s projection, which, though it greatly distorts the relative magnitudes, is the most convenient for purposes of navigation.
The parallels of latitude on the globe are everywhere equidistant. On the other hand, the meridians of longitude are furthest apart at the equator, and gradually approach till they meet at the poles.
In Mercator’s chart the meridians of longitude are drawn parallel and equidistant. The distortion in the direction of longitude resulting from this projection is counterbalanced by distorting the latitude to a proportionate extent; that is, the parallels of latitude are drawn further apart as the poles are approached.
Thus, on a chart of the world, the polar regions are greatly magnified when compared to the regions near the equator; still, as the degrees of latitude and those of longitude are proportionately magnified, the general shape of any particular tract is preserved.
The reason why this projection is the most adapted for purposes of navigation is that it produces no errors of direction; that is, if one place is north-west of another, it appears so on a Mercator’s chart.
It follows, from what has been said, that one scale of miles will not serve for a chart; as the scale is ever varying. The method of overcoming this difficulty while measuring the distance from one place to another on the chart will now be explained.
On inspecting an ordinary chart it will be found that the top of it is true north the bottom true south.
Along the top and bottom are graduated parallels, which are divided into degrees and minutes, and which enable us to distinguish the longitude of any position on the chart.
So, too, on the right and left sides of the chart we find graduated meridians also divided into degrees and minutes and which enable us to measure the latitude of any position on the chart.
Now, as a degree or a minute of latitude is the same length everywhere, we can use these graduated meridians as scales of miles. Each degree is divided into sixty minutes. A minute or nautical mile is about one-sixth longer than an English mile.
But as Mercator’s chart distorts the latitudes, each portion of the graduated meridians serves as a scale of miles only to that part of a chart immediately opposite to it, that is, on the same latitude. Consequently, to measure the distance between two places on the chart, for instance, Falmouth harbour in latitude 50° and Madeira in latitude 30°, we proceed as follows. The dividers are spread out till their points are over the two places on the chart. This distance is then measured off on the graduated meridian, by so placing the dividers on the scale that the mean latitude of the two places, that is, latitude 40°, is marked on the graduated meridian exactly halfway between the two points of the dividers.
The graduated parallels cannot, of course, be used as scales of miles for purposes of measurement.
While measuring distances on the large scale charts used for coasting purposes it matters little what portion of the graduated meridians be used as a scale, for the error will be imperceptible. It is only while using what are known as general charts, which extend across many degrees of latitude, that a considerable error will result from not measuring from the mean latitude.
Compasses are generally designed on various portions of a chart. These compasses usually indicate the magnetic and not the true bearings. (See Compass).
Various abbreviations are used on charts which are generally explained in a corner of the chart itself. Thus the nature of the bottom is indicated by sft for soft, c. for coarse, h. for hard, etc., while buoys are marked R. for red, H.S. for horizontally striped.
The soundings in fathoms or feet are indicated by numbers, the depth being calculated at low water ordinary spring tides. Where shoals sometimes dry, their height above low water spring tides is given by underlined numerals.
Roman numerals on a chart give the hour of high water at that spot at the full and change of the moon.
The velocity of the tide in knots is also indicated and its direction shown by arrows.
The yachtsman should provide himself with large scale Admiralty charts; for these alone can guide him into those shallow intricate channels frequented by small coasters only, which he will be so often tempted to enter.
The Mariner’s Compass.—Every one is more or less familiar with the use of the mariner’s compass, the instrument which enables us to know the direction in which a vessel is sailing when out of sight of land.
Fig. 45.
The compass card (Fig. 45) is divided into thirty-two points, so, as a circle contains 360°, the distance from one point to the next is 11¼°.
Sometimes a point is expressed in its angular value, that is, the number of degrees the point is west or east of the meridional line joining north and south. Thus N. by E. would be called N. 11¼ E., and N.E., N. 45° E.
Compass bearings are calculated to quarter points, as N.E. ¼ E., which signifies N.E. and a quarter of a point towards E.
The compass card moves freely on a pivot in the compass bowl, which in its turn is balanced on gimbals, enabling it to preserve a horizontal position despite the vessel’s rolling and pitching.
The binnacle or case in which the compass bowl is swung is provided with a lamp, so that the man steering can read the compass card by night.
Inside the bowl is a small mark, called the “lubber’s line,” which is exactly in a line with the head of the ship. That portion of the card which touches the lubber’s line therefore indicates the direction in which the vessel is pointing.
The jerky motion of a small craft will often cause an ordinary compass card to oscillate and even to completely revolve, so that the direction in which one is steering cannot be ascertained. It is therefore necessary to use a heavy compass card whose movement will be more sluggish. A spirit compass—such as Dent’s spirit compass—in which the card is surrounded by fluid—is the best adapted for small vessels.
But when a little craft is pitching quickly the very best compass will oscillate to some extent. In this case, one must observe the extreme points on either side reached by the swinging card and take the mean between them as the ship’s direction.
The needle points to the magnetic north, which coincides with the true north in certain portions of the earth only. The difference between the magnetic and real north is called the variation of the compass, it differs in different places, and is constantly but very slowly changing.
The variation at the mouth of the Thames, for instance, is now roughly 20° W., that is, the needle is dragged 20° to the west of north, so that if a vessel’s head be pointing true north, her compass will indicate a direction of about N.N.E.
The compasses designed on a chart generally show, as we have already explained, the magnetic and not the true bearings. Consequently, in order to ascertain the course that should be steered from one place to another, we lay one edge of the parallel rules on the two places on the chart, and by opening the rule we slide the other edge along—always preserving the direction—until it is on the centre of one of the compass designs on the chart. The direction thus indicated represents the course to be steered by compass.
But if the compasses on the chart are, as sometimes happens, true and not magnetic, the course shown by the rule is not the one to be steered by compass. We must, in this case, discover the variation existing in the locality—generally given on the chart—and convert the true course as indicated by the edge of the rule into a compass or magnetic course. To do this, if the variation is so many degrees west, the course to be steered will be that number of degrees east of the true course; if the variation is so many degrees east, the course to be steered will be that number of degrees west of the true course.
Where there is local attraction, as in an iron ship, the compass bearings will not be correct magnetic, but the needle will be dragged on one side or the other of the magnetic meridian. This error is called the deviation of the compass.
On board a wooden yacht, if certain precautions are observed, there should be no perceptible deviation of the compass. As iron ballast is generally used on a yacht, the compass should be as high as possible above it. If the boat have a well, the binnacle can at least be on a level with the raised hatch on the deck.
Care must be taken that no elongated iron mass, especially if vertical, such as a bolt, be near the compass.
Deviation is not uniform, like variation. When the vessel’s head is pointing about E. or W. the deviation is generally greatest, and it is different with every direction the vessel is turned to.
The deviation, if any, is ascertained by what is termed swinging the vessel. The correct magnetic bearing of some distant object is first obtained. The vessel is then slowly swung round—this can often be done by carrying the mooring line along one side of the deck aft, and then along the other side to the bows again—and as the vessel’s head comes to each point of the compass, a compass bearing is taken of the object, and the difference between that bearing and the true magnetic one is noted.
A table can then be drawn out showing the deviation to be applied for each point of the compass towards which a vessel is steering.
When steering by compass, do not keep the eyes constantly fixed on the compass card, as this is extremely wearying, especially by night. When you have got the vessel on her course, get some object ahead—a distant vessel, a cloud, a star, if no land is in sight—in line with the mast, or one of the shrouds, and steer for that; referring only occasionally to the compass, so as to correct the direction and get a new mark to steer for when necessary.
The Log Ship and Line are employed to calculate the speed at which a vessel is travelling through the water. The log ship (Fig. 46) is a quadrant-shaped piece of wood, loaded with lead at the bottom, so that it may preserve an upright position in the water. It is attached to the log line by means of a bridle.
Fig. 46.
The ordinary log line is 120 fathoms long. The log glass generally used is a common sand-glass, running out in 28 seconds. The line is divided into equal distances by knots, each distance being the same fraction of a nautical mile as 28 seconds is of one hour; the distance therefore between two knots is about 47 feet.
A bit of bunting is attached to the line about 12 fathoms from the log ship. These 12 fathoms are called the stray line.
The process known as “heaving the log” is performed as follows: One hand stands by, with the glass in hand, full end downwards; another hand heaves the log ship overboard, which floats away astern; the line is then steadily paid out from the reel, in such a way that no strain is put on the log ship.
At the moment when the piece of bunting marking the stray line goes overboard, the glass is smartly turned. As soon as the sand has run out, the man holding the glass calls out, “Stop!” and the log line is suddenly checked. The number of knots that have been reeled off represent the number of sea miles the vessel is sailing an hour.
Several forms of self-registering logs are now in general use. These are towed astern, and communicate the revolutions of a screw rotator to a register—either overboard or on the taffrail of the vessel—which indicates the distance run.
These patent logs do not act in an altogether satisfactory way on small sailing craft. They generally under log the distance run when the vessel is sailing slowly, and are more adapted for use on steamers. For ordinary cruising purposes, on a small fore-and-after, we prefer the old-fashioned log ship and line, and it is not very often that one has occasion to use even that.
The Lead Line.—Two leads are employed on vessels—the deep sea lead weighing 28 lb., and the hand lead weighing 14 lb. The latter, or even a lead weighing somewhat less, is sufficient for a small yacht.
The line used for a hand lead is 25 fathoms long, and is generally marked as follows:—
| At | 2 | fathoms, | Leather, with two ends. |
| 3 | ” | Leather, with three ends. | |
| 5 | ” | White calico. | |
| 7 | ” | Red bunting. | |
| 10 | ” | Leather, with hole through it. | |
| 13 | ” | Blue serge. | |
| 15 | ” | White calico. | |
| 17 | ” | Red bunting. | |
| 20 | ” | Strand, with two knots in it. |
It is possible, by the different feel of the materials used, to tell what mark is in one’s hand in the dark. The above depths are called marks; the intervening depths in fathoms which are unmarked are called the deeps. Thus, in five fathoms, the leadsman sings out, “By the mark five,” in eleven fathoms, “By the deep eleven.” He also calls out the halves and quarters of fathoms thus, “And a half six,” for six and a half fathoms, “A quarter less six,” for five fathoms and three-quarters.
To sound when the vessel is under way, swing the lead round and throw it as far forward as possible, so that the lead be at the bottom and the line tight from it to the hand, when the vessel is just over the lead.
If the lead be hove properly, so that it draws the line through the hands, it is easy to tell when it has reached the bottom, by the sudden withdrawal of the strain.
When sailing on very shallow waters, soundings can be taken much quicker with a pole or boathook than with a lead.
There is a hollow at the heel of a lead which can be filled—armed as it is termed—with tallow; a specimen of the bottom—mud, sand, or shingle—is brought up with the lead, and this, by reference to the chart, which generally marks the nature of the bottom, may enable us to find our position.