C (letter)

In the International Code of Signals the single letter C means Yes (or AffIrm¬ative). Charlie in the phonetic alphabet -0-0 in Morse code.

Cabin cruiser

Invariably a powered craft with sleeping accommodation. A sailing craft with similar accommodation may be implied if the word Cruiser is used alone, though the context is important, and usage varies geographically. On the Norfolk Broads for example, cruisers are powered craft, those with sails are called yachts.


(1) May be of wire, rope or chain, but is the link between a boat and her anchor. (2) A measure of distance equal to one-tenth of a Nautical Mile. A nautical mile being 6,080 feet, a cable is just over 600 feet, and may be taken as 200 yards for most purposes.


Heavy ropes are often made of three laid up together in a left-handed twist. Each of the component ropes in cable-lay is Hawser-laid and consists of three strands (not ropes) laid up with a right-handed twist. Heavy hawsers are commonly cable-laid, whereas hawser-laid ropes are not often used as hawsers.

Cam cleat

A type of cleat which uses two sprung cams to grip the rope.


(1) Almost always of decks, and means curved athwartships, as in a cambered road. Camber sheds water, augments strength because it forms an arch structure, and can permit greater headroom while avoiding unsightliness. Al¬though a cambered deck is a nuisance when you want to sunbathe and your tea-mug may not stand level, it can be advantageous in a heeled sailing boat. In that case the weather side of the deck will be more nearly level than it would be if uncambered. But the lee deck will be correspondingly steeper. (2) The fore and aft curvature in a sail. Also known as Flow. Camber should be fuller for light winds, flatter for strong winds.


An unballasted foil, usually mounted well forward in the hull, used to resist leeway. Canards can be fixed or lifting and a boat may have more than one.

Canbus (or Can)

A bus system, commonly used in cars for sharing data and switching information, and increasingly found on boats owing to its similarity to NMEA2000


Although everybody knows of at least two types of canoe – the Indian birch-bark type and the smaller more compact Eskimo kayak, there are also sailing canoes of which the international ten-square-metre class is best known in Europe. The United States was the home of sailing canoes of many types, some of them very large. In ordinary sailing cruisers the term Canoe body applies to a hull of shallow form to which the keel is a separate appendage. Canoe stern (illustrated under Stern) is one which rises from the water like a counter, but has a rounded end.

Canting keel

A ballasted keel that, instead of being fixed laterally, can be canted to windward to increase the righting moment

Canting Rig

A rig that can, depending on its design, be canted to windward or to leeward.


On a gaff-rigged boat the mast has a cap sprouting a ring through which the topmast can slide. The shrouds leading to the cap are called Cap shrouds, and people still use the term for the main shrouds of a Bermudan-rigged mast. (The capping piece on the top of a mast is the Truck.)


Any boat is capsized if she turns upside-down, but usage has it that a dinghy is capsized if her mast reaches the water, whereas a cabin boat at such an extreme angle ( ninety degrees) would not be capsized but ‘On her beam ends’. Capsize is also used of things turned upside down by sailors for their own good reasons: a coil of rope may be capsized, and so may a popsie.


A windlass with upright barrel, turned by bars radiating like spokes. Not to be found among today’s pleasure craft, the nearest thing being the sheet Winch which is also normally mounted with barrel axis verticaL


Some sheets are led to a track, where they are attached to a sliding plate or a miniature flat-bed truck on rollers. This is a car, which may also be called a Traveller.

Carbine hook

A hook with spring closure, basically similar to the hook on a dog-lead or a watch-chain, but made to a higher specification. Compare with Snap Shackle.

Carbon fibre

A strong, lightweight material used in the manufacture of spars, hulls, and sails.

Cardinal buoyage system

Is one in which a localised danger is marked by buoys situated to North, East, South and West of it. (Please see IALA buoyage system.)

Cardinal points

The four principal points of the compass, North, East, South and West. But the antique type of compass had thirty-two points in all, arrived by successive halving. Each Point was equivalent to 111/4 degrees of the modern compass.


To haul a boat down until her mast approaches the horizontal, and her hull is on its beam ends. May be done afloat or ashore. The purpose is to gain access to the hull bottom.


Fore and aft timbers to which deck beams, cabin sides, etc., are attached.

Carry away

To break or collapse. An intransitive verb in this usage. If a shroud carries away, the mast may fall on your head. Subsequently they may come and carry you away, which is the transitive and non-nautical usage.

Carry helm

A boat ‘carries weather helm’ when the helmsman has to hold the helm to weather to keep her straight. Similarly she may ‘carry lee helm’.

Carry her way

A boat carries her way when she continues moving by her own momentum after the propelling force has ceased to act.


The form of wooden hull construction in which the planks are assembled with fine gaps between. These gaps are then caulked with cotton (or oakum) and Payed with stopping. The whole surface is then rubbed down smooth before painting.


The sounding lead is cast. To take a sounding somebody has to ‘Make a cast of the lead’. When leaving an anchorage under sail, and supposing the boat to be lying head to wind at the time, there comes a moment when the helmsman must Cast the boat either to port or starboard in order to make a Board. While the boat is still lying to her anchor the rudder will be effective if there is any tidal stream running. In that case the vessel may be made to take a Sheer to one side or the other. But as soon as the anchor comes free you give her a Cast.

Cast off

To let go from a mooring. To undo a rope, free a dinghy.

Cat, to

To secure an anchor on board. Some boats have a Cat-head, which is in fact a small crane or spar to which the anchor is lifted and at which it may be stowed.


The term cat has been applied to a variety of boats, but currently it will normally refer to an American type of sailing boat with shallow draft, very great beam, transom stem and centreboard. The boat is rigged with a single gaff sail on a mast stepped right in the bows, as in the illustration. The single-sail rig is also knoWn as Cat rig or sometimes as Una rig after a famous cat-boat of the last cen¬tury which was named Una.


An additive which initiates the curing of polyester resin. The resin is normally supplied (at least for amateur use) with an accelerator already mixed in. The catalyst’s role is simple to trigger the cure and set it going. Only a minute amount of catalyst is needed, and the maker’s instructions must be followed carefully. (Please see Polyester.)


(1) In common parlance a Cat, but not a Cat-boat. To private owners the word means a twin-hulled boat, usually sail, but sometimes power. A sailing catamaran does not need ballast, but gains her stability by standing wide. Her long, lean hulls coupled with her light weight make her generally a faster boat than a single-hulled craft of the same cost.
(2) Nothing at all like the high-speed craft above, but simply a collection of timber balks, railway sleepers or the like, held together with spikes or lashings so as to make a raft. Sometimes called a Flat or a float, these rafts are used as floating platforms by chaps painting topsides or doing other work on boats which are afloat.

Catch a turn

To take a turn around a bollard, post, cleat or the like. Usually implies swiftness.

Cathedral hull

A hull whose bottom is in the form of a triple V. When at rest or moving slowly, all three Vs are immersed, but at speed the hull rises and the outer Vs barely touch the water

Cathodic protection

Use of a sacrificial anode to protect more important fittings from becoming victims of galvanic corrosion


A gentle puff of wind.


Carvel hulls and Laid decks are formed of planks between which gaps are left, later to be filled by caulking. In a Carvel hull the gaps are V-shaped, with the wider part outward, and they are caulked first by ramming cotton or oakum into the bottom of the gap and then by filling with Marine glue, or by some modern compound. Although caulking is properly the first part of this process, and Paying the second part, most people nowadays tend to use ‘caulk’ alone, rather than trou¬bling to speak of ‘caulk and pay’, which would be precise. Caulking irons are spe¬cially shaped tools with which the cotton or oakum is driven, with the aid of a Caulking mallet. A Paying kettle has a specially shaped spout to ease the pouring of the warmed marine glue between the deck planks. (Incidentally, marine glue is not an adhesive, but waterproof glue is.)


This is the word that architects use for the hollow moulding that most boatbuilders call the Cove Line. Still, some boating people say ‘cavetto’, and some even say ‘caveta’, so I thought I would mention the fact.


A phenomenon associated with a propeller which is being driven too fast, whose blade area is too small for the power it is expected to absorb, or which is working in badly disturbed water. Effectively the water parts from the blade surface, leaving a void filled with vapour or air; the void then collapses and the water falls back on to the blade with considerable force. This process is repeated with rapidity, eroding the blade and vitiating its propulsive efficiency. (A similar effect can erode the hull bottom of a very high speed craft.) In private craft, cavitation when running straight is a sign that the wrong propeller is fitted. When turning, even the right propeller may cavitate if the turn is very sharp: to avoid damage, throttle back or turn less sharply.


Decorative linings to the cabin sides, but not normally overhead. In a boat the ceilings correspond to the walls of a room ashore, and the Deckhead corresponds to the domestic ceiling.

Celestial navigation

Finding one’s position on the surface of the earth by using the stars and other heavenly bodies as reference points. The essential tools are a Sextant to measure angles between the horizon and a celestial body, a Chronometer to give Greenwich mean time (time is also monitored by radio signals) and a pre-calculated table of star positions which are known as the Ephemera and are found in various Almanacs.

Centre of buoyancy

The single point through which the buoyant force of the water pressure may be thought to act. If you are familiar with the idea of the Centre of gravity of a body as being the point about which it would balance, then centre of buoyancy is the same sort of thing the other way up. If you could push downward on a model boat with your finger precisely at her centre of buoyancy, she would go down without tilting. (But as she went down her centre of buoyancy would certainly shift, because of the changing shape of the immersed part of the hull … )

Centre of effort

And this will be a good place to consider the Centre of Lateral Resistance too, since the two are so commonly related in design work. The CE is the point at which the wind forces on a sail are assumed to be centred. It is akin to the concept of ‘centre of gravity’. Conventionally the CE of a triangular sail is assumed to be at its centre of area (where lines from each apex to the mid-point of the opposite side cross each other), and the CE of the whole rig is found by proportioning between sails according to their areas. The CLR of the hull is likewise assumed to lie at the centre of all the underwater parts, but since it is usually only the fore-and-aft position which is thought to be significant, this is found by cutting out the shape of those parts in cardboard and balancing the pattern on a knife-edge. (The knife is set at a right angle to the waterline, of course.) Unfortunately neither of these simple methods for finding ‘centres’ has any relation to reality. The CE shown on the designer’s sail-plan is well removed from the true centre of aerodynamic pressure on most points of sailing; and the CLR is no better. But convention has it that if the CE is some ten to fifteen percent of the waterline length ahead of the CLR the boat will balance quite well, with modest weather helm. In fact, the displacement of the aerodynamic thrust to leeward as the boat heels has far more luffmg effect that the fore-and-aft relationship between the CE and CLR so neatly shown on the drawing of an upright boat with flat sails.


(and centre plate) A centreboard is a retractable keel surface fitted on the centreline of the boat. (Compare with Leeboard.) It mayor may not be ballasted, but its primary function is to provide underwater area to create lateral resistance and so to minimise sideways movement by a boat under sail. ‘Board’ is normally used of a wooden one, and ‘plate’ of metal, though one is not likely to be ostracised for talking about a ‘steel centreboard’. Since the Board, as it is often called, works through a slot in the keel of the boat, it is necessary to keep water out. This is done by making a casing, called the Trunk, just big enough to accommodate the board, and rising above the level of the waterline. It makes a suitable plinth for the cabin table in small boats. In larger boats the top of the trunk may be below the waterline, and even beneath the cabin sole, in which case it must be fully sealed, though the lifting tackle may then run in a pipe whose upper end is sufficiently high. A centreboard boat which is allowed to take the ground regularly between tides may have so much mud forced into her trunk that the board will not drop, even though of great weight. Centreboards have been used for both racing and cruising craft, large and small, but especially for small sailing dinghies. Some have had pairs of boards, disposed fore and aft or laterally. The heavier ones are raised by winch or by block and tackle, but some make use of electric or hydraulic power.


European Inland Waterways Regulations


Form to register vessel details with HM Coastguard

Chain plates

The metal fittings on each side of the hull to which the shrouds are attached. It is much more sensible to call them Shroud plates as is commonly done nowadays, though the old term still persists. (Old ships had chains below the Dead-eyes of their shrouds.)

Chain sheet

See reaching sheet.


(1) The deeper part of the water, often buoyed as the main route. The bit where you ought to have been when you go aground.
(2) A small balk of timber fitted to the side of the hull for the purpose of spreading the shrouds to a wider angle. Fitted in pairs, one each side of the boat, of course. Formerly such timbers were called chain-wales, a Wale being any raised strake, and they spread the chains below the dead-eyes. For that reason the part of the ship where the shrouds approach the hull is still sometimes called the Chains. ‘Standing in the chains’ still means standing on the edge of the deck by the shrouds – a good place for casting the lead, or for preparing to jump ashore.


The pattern, or signal or code of a flashing light or a sound signal by which it can be identified. Examples: Quick Flashing Light; Occulting light, and so forth.

Charlie Noble

The dome on top of a chimney. But don’t ask me why, or who he was!


A map of the sea, showing shore lines, depths, useful marks and buoys. All British charts are based in the first instance on the work of the Hydrographer of the Navy, who prepares the Admiralty charts. These are used as references by some firms who specialise in charts for yachtsmen and private owners. Often these special charts give better value because they combine information from several Admiralty charts on to a single sheet, and also add harbour plans, pilotage information and so forth. Charts are listed in the Admiralty Catalogue of Charts, and they are obtained from chart agents, who are usually also chandler’s shops. ‘Class A’ chart agents amend their charts and keep them up to date day-by-day. British agents are listed in the Admiralty catalogue, which can be obtained from HMSO (or from the agents themselves) for a very modest sum. In the USA charts are produced by the US Defense Mapping Agency in Washington, who collaborate with the US Coast Guard in publishing Notices to Mariners, containing details of changes and corrections.

Chart datum

The sea level used as a reference point for the soundings given on Admiralty charts, and for the tidal heights in Tide tables. Likewise it is the reference level for the drying height of a sandbank. The current chart datum is the level of the Lowest Astronomical Tide, which is the lowest water level predict¬able. Lower levels are possible, for example by the combination of very strong wind with the LAT, but for practical purposes one assumes that the tide will not fall lower than chart datum. Thus if a sounding is shown as one metre, then there is a very high probability that there will never be less than one metre at that point, and there will usually be more. (See Tide and Height of tide.)

Chart plotter

An electronic device for displaying charts and planning navigation.


To hire a vessel. The document recording the contract is the Charter party.


To check a rope is to ease it out slowly and under control. The nauti¬cal usage of check in relation to ropes is the opposite of the horseman’s in relation to the reins. But when a seaman says of a boat ‘Check her way’ he means ‘stop’ or ‘restrain’ as a landsman would. (See to Start.)


Block of wood fixed against the side of something, such as a mast. A Cheek block is a hollowed-out cheek containing a sheave, such as is fitted to a mast for a Topping lift.

Cheese, to

To coil a rope on the deck in a flat spiral, one layer thick, so that it looks somewhat like a tightly wound watch-spring. (See Fake and Flake.)


The angle where the bottom of a hull meets the side. A round-bilge hull has no chines, but a boat built from flat sheets (plywood, say) has one or more chines each side, and is known as a hard-chine boat. (See also Bilge.)

Chinese gybe

A situation, usually resulting from a gybe, where the upper part of the sail is to one side of the mast, and the lower to the other. It occurs because the boom is allowed to lift up too high. The term itself is an unwarranted occidental jibe, for Chinese boats with their fully battened lugsails are incapable of getting themselves into this specifically Bermudan predicament.


A simple gadget for measuring speed. A flat, triangular-shaped board has a bridle consisting of a line from each corner, meeting at a single logline. The board is weighted at one edge so that it will float upright when dropped over the stern. In that attitude it remains stationary in the water and draws out the logline whose length is marked out with knots at regular intervals. The number of knots which run out in a given time provides a measure of the speed. For example, if you want to time over half a minute, which is 1/120 part of an hour, then make the distance between each knot equal to 1/120 part of a nautical mile. Then the num¬ber of knots that run out in the half minute will be the ship’s speed in knots. 1/120 of a nautical mile is 50.6 ft.lf that’s too long, measure over 15 seconds and space the knots at 25.3 ft.


A shaped metal fitting in Toe-rail or Bulwark which allows a mooring line to pass without chafe. In Britain it is called a Fairlead.


When the two blocks of a tackle meet and no further movement is possible. The phrase has long since been adopted by, and adapted to, everyday life ashore. The situation also known as ‘two blocks’.

Choke the luff, to

To prevent a tackle running, by jamming a bight of the fall between a block and one of the rope parts.


A sea which is short and small. Also a Lop. The adjective is Choppy, but nobody seems to say ‘loppy’.

Chopped strand mat

A non-woven form of glass cloth used for reinforcing polyester resin. The strands of glassfibre are two or three inches long and they lie in random directions, held into a sheet by a small amount of resin. There is just enough resin to retain them in this form for convenient handling, and when laid in place the mat is thoroughly permeated by a far greater amount of polyester resin. Most ‘fibreglass’ boats are built principally of CSM, though woven rovings are also used.


The fore-and-aft measurement of a keel, rudder or sail at a given point


An accurate clock or watch of a standard that makes it suitable for navigation. By ‘accuracy’ I mean that it maintains a steady and known speed. It is not important that it gains or loses a little each day, so long as the gain or loss is constant and therefore predictable. This is known as the chronometer’s ‘Rate’.

Class boat

A boat built to conform to limiting rules for handicap racing – or built to conform to a known Rating rule for racing.


A measure of the standard of a yacht’s construction as certified by one of the ‘classification societies’ such as the American Bureau of Shipping, Lloyds Register, Bureau Veritas (France), or the like. In Britain, a boat built to Lloyds standards and under their supervision may, for example, be classed ‘100 A1’, but she will lose that rating if she is not inspected by Lloyds at specified intervals. At such regular surveys Lloyds will specify what corrective work must be done to enable her to remain ‘in class’.

Claw off, to

To beat away from a lee-shore. This is an expression used to emphasise moments of drama, and seems to be used mainly in bar-room arguments about the relative merits of various types of boat. It is the sort of phrase that mixes well with ‘in my humble opinion …’


A fitting for the quick attachment of a rope without the use of a knot or hitch. The cleat proper, ancient and respectable, is roughly like a short stemmed T, with two ‘horns’ which might also be described as arms. But there are various patent cleats of the jamming kind, including Clamcleat which has a V-shaped groove with ridges running down the inner faces to coax the rope into the nip of the V. Cleat can also be used as a verb.

Clench, to

A landsman would say ‘to rivet’. To draw together two components, usually timber, with a copper Boat-nail. The nail is square in section and its end is spread over a cup-shaped washer called a rove. Clinker-built hulls are built by clenching all the planks together, which is why many people quite logically insist on calling them Clencher-built. Please yourself.

Clevis pin

The pin which closes the U-shaped fork on the end of a rigging-screw, for example, or which closes those small shackles made from bent strip. The clevis pin does not have a threaded end, but is usually drilled to take a split-pin or split-ring.


The lower after corner of a fore-and-aft sail, or the two lower corners of a squaresail if you are lucky enough to own one. The lower forward corner is the Tack, and the top corner is the Head.

Clinker construction

Also Clencher, according to taste. A form of hull construction in which the edges of the planks overlap, and are riveted together with copper boatnails. It makes a structure which is light for its strength, and which needs no caulking. The overlapping edges are called the Lands, and the lands nearly always face downward though there have been a few exceptions. The succession of small, downward-facing steps prevent water flowing up the side of the hull and make for a dry boat. On the other hand there can be a great deal of water noise with a clinker hull.

Clipper bow

The shape of bow in which the stem forms a hollow curve on its underside – often running into a bowsprit. The sections of such a bow are flared and hollow above the waterline.

Close, to

To approach, or come nearer, as in “we’ll close the land in a little while and see if we can identify any features … ”


The point of sailing nearest to the wind – sometimes as close as thirty degrees off the wind, but more often on cruising boats in the region of forty-five degrees. (Please see Reach.)


A loose term, used by salesmen or vain-glorious owners to imply that a boat sails closer to the wind than the listener might expect.

Clove hitch

The most common hitch for making fast to a samson post or a rail.


Centre of Lateral Resistance.


A short boom fitted to the foot of a staysail or jib. Rare in the UK but more familiar in the USA.


The weight which holds a mooring chain on the bottom.


A lever assembly, most often used to jam halyards.


Course Made Good. Also known as Track. The average course made by a boat after tide, leeway and other external factors have been taken into account. This term differs from Course Over Ground especially when beating. See: Course.

Coach roof

The part of a cabin which stands up above deck level. (See House.)


A vertical ridge or barrier, of wood, steel, fibreglass, etc., whose purpose is to keep water out. A cockpit usually has a coaming down each side, and perhaps all round. A deck hatch has one all round. Some hatches have a double coaming so that any water which gets past the outer one is channelled between the two and escapes through drains.


A Yorkshire beach-boat of very distinctive shape. She has a snaking sheer, hollow shoulders and buttocks, but a full and firm mid-body. The rudder is of very high aspect-ratio, deep and knifelike. Some people think the world of these boats, which may be used under oars, motor or lugsail. Notice the deep rudder which is unshipped for beaching – it must be deep to balance the power of that deep forefoot.

Cocked hat

The triangular area contained within three position lines drawn on a chart. If there were such a thing as perfect precision all position lines would cross at a point. People generally assume that the ship’s position at the time of taking the fixes was somewhere inside the triangle, and for want of anything better will put the plot in the middle. But avoid being deluded by the idea that the ship was really at that point.


The ‘dug-out’ where chaps like me cower for shelter from the bombardment of sea, wind, snow and hail. If you have a reasonable area of deck around your cockpit it is a good piece of one-upmanship to call it the Well.

Cod’s head and mackerel tail

The shape of a sailing-boat hull which was popular in times past, where the bow is very full and then fines away toward the stern. Current design of the sensible type has the maximum beam more or less amidships, with bow and stern waterlines well balanced, though some racing boats have the maximum beam well aft.

Code Zero

A free-flying lightweight reaching headsail.


Standards issued by the MCA for British-flagged boats intending to be used for professional purposes, ie. Chartering or as a passenger boat


Small three strand rope used for lashings. Like thick string. Hambro line is similar, but neither term is much used now that we are in the era of synthetic fibres.

Coffee grinder

A winch drive system for quickly sheeting the headsails of large and expensive boats. Commonly stands on a pedestal in the centre of the cockpit, serving port and starboard sheet in turn, and is actuated by crank-handles which drive internal gears.


Course Over Ground. The course made by a boat at any given time with tide and leeway taken into account.


Coconut fibres used for making rope. At one time coir rope was used for heavy warps, but it is now rarely seen except as fendering of one kind or another.

Cold moulding

A form of wooden-hull construction in which thin veneers are successively glued together over a male mould. Makes a very strong and watertight shell which is in fact tailored plywood. Wooden hulls may also be hot-moulded, but the oven large enough to take a hull is an expensive item of equipment, and glue which cures at ordinary temperatures makes the job easier. Hulls are also moulded in glass-reinforced resin, and planked timber hulls are built over Moulds.

Collision Regulations

The odd name by which most people know the International Regulations for Preventing Collisions at Sea, which should be read, re-read, studied and re-studied.


A compaction of Collision Regulations, as you doubtless guessed.

Combined lantern

Please see Tricolour lamp.

Coming home

If you pull on an anchor cable and the anchor comes towards the ship instead of the ship going towards the anchor, then you can tell the skipper ‘The anchor’s coming home’. In other words it’s not holding.


The president, or senior officer, of a yacht club.


The entry into the cabin. In modern small boats just a doorway through the main bulkhead, because most small boats don’t have a companion; or if they do, people call it a Dog-house wherever possible. And while we’re on the subject, you may wonder, as I did for many years, what the devil this has to do with friendship. Not much, unless you go right back to Roman times since both words started life from the idea of ‘with bread’. The human companion shared your bread, but ‘companaticum’ was what you had with your bread – cheese, butter, Gentleman’s Relish and the like. Later the Italians liked to have a little storehouse on deck for cheese and suchlike stores which they called ‘campagna’. The Dutch and English picked up the word, the Dutch using it to mean quarterdeck, and the English bending it into ‘companion’ and using it to describe any small deckhouse, and even a skylight. So there …


Well, you know, a little magnet, balanced on a pivot so that it is free to point always to the Magnetic North no matter which way the ship points. They come in all types and sizes, and you just can’t do without one. Two are even better on any sea-going craft. (See Grid compass and Point.)


Traditionally used to describe a boat built from different materials, such as glassfibre/FRP for the hull and wood for the deck, or vice versa. Now more commonly applied to structures incorporating a combination of fibres including, for example, carbon, vinylester, epoxy, aramids and core materials.

Con, to

Personally to steer your ship, as in ‘I’ll con the ship if you make the tea’. To control her. This word is of virtually no value to private boat-owners, unless uncommonly affected in their speech, but it is invaluable in the solving of crossword puzzles.


A radio navigation aid, working on ‘long wave’, which needed nothing more than the special Consol chart and a radio receiver. If the receiver had a beat frequency oscillator to make the Consol dots and dashes more distinct, so much the better, but it was essentially a simple system in which you had little more to do than to count the dots and dashes from two or more Consol transmitters. But when ships were able to use more sophisticated (and more accurate) aids, who wanted Consol? Only private owners in their little boats, so Consol was closed down.


An upstanding plinth or box designed to support such things as a steering wheel, a set of instruments, the throttle levers and so forth.


A light, stiff material, such as balsa, honeycomb matrix or sheet foam, incorporated in a laminate to increase its rigidity for a given weight.


Please see Galvanic corrosion.


The overhanging part of the stern, especially when projecting markedly aft of the rudder. A flat stern without overhang is called a Transom.


The direction in which the ship is pointing or heading. The compass course is the direction expressed in terms of compass degrees. When there is a cross-current, the vessel is not moving in the same direction as that in which she is heading, and it is customary to describe her direction over the sea-bed as the course made good. The distinction is important, and I prefer to use the word Track for the CMG, which is what you plot on your chart. But feel free to suit yourself.

Course up

Radar plot or chart shown with the vessel’s planned course pointing directly up the screen, as chosen by a GPS route or GoTo (see Head up).

Course-setting protractor

A navigational protractor, normally scribed on a circle of transparent plastic, and having an arm or rule pivoted at its centre. The rule makes it very convenient to lay off courses, or bearings without recourse to the Parallel rules.

Courtesy flag

When entering a foreign port, a boat should fly the flag of that country from her starboard Spreader, continuing to fly her own national ensign from its usual staff. Take care not to put two national flags on a common hoist or staff, for one will then inevitably be below the other, national dignity will be offended, and war will probably break out.


A moulding cut into a wooden boat’s topsides a few centimetres below the sheer, and running from stem to stern (or almost). The section of this groove is the arc of a circle. Its function is to embellish, and for best effect it is gilded. A hull moulded in glass-reinforced resin normally has a painted cove line, or applied coloured adhesive tape.

Covering board

A plank forming the edge of the deck surface, inside the gunwale. Whereas deck planks may be straight, covering boards are curved to the plan form of the hull at deck level.


Closest Point of Approach. The point at which the distance between two vessels or objects, of which at least one is in motion, will reach its minimum value. Common in radar and AIS.


very popular and efficient type of ‘plough’ anchor.


A framework of wood or steel designed to support a hull ashore.


A short arm or bracket at the masthead, to which a forestay (or backstay) is made fast.


A vessel that is crank is one that is Tender – that’s to say she heels too easily. If very crank she may be dangerous. Tender is the usual word nowadays, but Crank gives you that certain air …

Cranse iron

A metal band with eyes which is fitted to the bowsprit-end to receive the bobstay, shrouds, etc.

Crevice corrosion

A form of Galvanic corrosion, notably suffered by stainless steels. When one end of a stainless-steel bolt, for example, is exposed to sea water and the other end is buried in timber so that is shielded, and two ends of the bolt act as if they were of two different materials. Wasting of the bolt follows.


An eye in the edge of a sail, formed in the roping and usually fitted with a metal or plastic thimble against chafe. There is a cringle at each corner (Clew cringle etc.), and others for reefing. (It might be a good idea to see Earing and Grommet while we are on the subject. .. )


A piece of timber with a natural curve in it – used to make the curved part of the stem, etc.


Two or more bearings from which crossing position lines can be drawn on the chart to give a Fix.


A strut fitted across the mast whose ends support the inward thrust of the shrouds. A cross-tree should be a single unit, whereas many modern yachts have a pair of separate struts, one on each side of the mast, and these are called Spreaders. The latter is a more satisfactory term for small boats.


The crown of an anchor is the farthest end from the chain – the point at which you would hitch a line in order to withdraw it from the mud.

Crown knot

The first step in making a Back splice.


A cruise implies a voyage of at least several days, calling at various places en route. Each trip from one haven to the next is a Passage.

Cruise, to

To take a holiday on a boat, moving from place to place and spending nights away from base. The nights maybe passed under way, at anchor, or even in splendid hotels ashore, but the normal thing is to sleep aboard. One may cruise in an open boat, on the sea or on inland waters. The main thing, as Hilaire Belloc was at pains to emphasise, is that cruising is not racing. Another way of not racing is to go ‘day-sailing’, a term which implies that the boat returns to the same haven each night.


The meaning of this word depends very much on circumstances and context. If there is no other clue, it probably means a motor cruiser – a motor boat with habitable accommodation. If the context is one of sailing craft then it means a boat whose design was not constrained by any arbitrary rating formulae devised for the amusement of racing yachtsmen. If compounded in the form Cruiser-racer it implies that the boat was designed to fit the rating formula but that the builder hopes he can sell her to cruising people in spite of that.

Cruising chute

Asymmetric spinnaker for cruising boats. The tack is attached to the yacht’s bow.


(1) A device to support the boom. Sometimes takes the form of a plank with a notch at the top like a Y, whence cometh the name which is the same as the crutch of a tree or the crotch of a person. Sometimes takes the form of a metal strut or crossed struts. But a goal-post type of support with two verticals and a cross-piece is known as a Gallows. (2) A rowlock crutch is the purist’s name for what I call a Rowlock. A metal object of familiar form (like a Y but with a top that’s more of a U than a V) which supports an oar for rowing. It is called a crutch because it is like one of nature’s crutches, and the hole it drops into is a Rowlock. ‘strue. But I’ll still call crutches rowlocks.


A small space, too small to be a cabin and too big to be a locker. Usually right in the Forepeak of a half-decked boat.


A control line, running to an eye in the luff of a mainsail, used to control luff tension and thus the sail’s shape and draught.


Please see Stream.

Cut splice

A form of splice used to make an eye in the middle of a rope rather than at an end. The rope is cut, and each fresh end is then spliced into the other rope sufficiently far along to make the eye. Alternatively, a separate short length of rope is spliced in. (Although the aetiology of the name is interesting, I would prefer not to delve into it in public … )

Cutless bearing

A propeller-shaft bearing in the form of a rubber sleeve. It is used at the outboard end of the shaft and is lubricated by water which is appropriate for rubber. The metal housing of the bearing has small scoops to collect water as the boat moves forward and to direct it to the bearing, so care should be taken not to fill these scoops with paint.


Nowadays a cutter is a sailing vessel with one mainsail and two headsails – namely the Staysail and the Jib (see sketch under Rig). A vessel normally sailed with that rig remains a cutter even though one or more of the headsails is handed, and even if a Flying jib is occasionally added to make three headsails. This word is a good example of the way in which the language changes, for in the past it was either a ship-of-war’s boat, used for fetching stores etc., or a fast sailing boat used by revenue men, which like as not carried a squaresail on her single mast. In those days the word Cutter could relate more to the boat that to the rig, whereas nowadays it refers only to the rig. (See Sloop.)


The part of the Stem at the waterline.


A revolving tropical storm in which the winds circulate around a low-pressure centre, the whole system moving linearly at the same time. This type of storm goes under different names in different parts of the world, ‘typhoon’ and ‘hurricane’ being the most familiar. A full-scale cyclone is rare in Northern European waters, but the type of weather system which centres around a low-pressure area is called Cyclonic, and that is extremely common in these areas. In the northern hemisphere cyclonic winds run anti-clockwise in a cyclonic system (generally bad weather) and clockwise for an anti-cyclone (good weather). In the southern hemisphere these directions of rotation are reversed.