In the International Code of Signals the single letter G means, ‘1 require a pilot’, and may be made by flag or any other method of signalling. It is Golf in the phonetic alphabet. In Morse code it is – – •. (Note that a fishing vessel when on her fishing grounds may make G to mean ‘1 am hauling my nets’.)

General arrangement. A plan view of a boat’s accommodation.

The spar at the head of a four-sided fore-and-aft sail. May be short or long. (A Gunter mainsail is strictly speaking four-sided, though two of the sides almost form a straight line. The spar at the upper end of a gunter luff is called the Yard.)

Not a very precise term, and used by some to describe any fresh breeze they happen to have been out in. But the Met. men use it for winds of Beaufort force 8 and 9, embracing wind speeds in the range 34-47 miles an hour.

European-sponsored equivalent to GPS. Differs from GPS and GLONASS in being entirely non-military.

The tea-tray sized area in one corner of the cabin where you fry bacon and heat beans. For what is often little more than a cupboard the word might seem pretentious, but the usage is quite normal, and it embraces cooker, sink, and pan stowage as well as working top.

Rare, but could be used more. A clinker boat of some thirty feet, propelled by oars or sail and part-decked. On the flicks you would have seen Admiral Hornblower being pulled ashore in a galley on important occasions. (When he was a captain he would have had a Gig, similar, but smaller.)

A support for the lowered main boom, consisting of two uprights and a cross-bar. Unlike a crutch it is normally a fixture.

Corrosion that occurs when dissimilar metals are connected and immersed in salt water.

An electrical component that isolates metallic elements from any stray currents in the marina. Without the isolator, a galvanic corrosion path may be created via the shore power connection.

As far as we are concerned it is to plate iron or steel with a layer of zinc, as protection against rust. Properly it would apply to any type of electro-plating, but usage now has Galvanise for non-electric processes, such as ‘hot-dip’ galvanising’ or even ‘cold galvanising’ in which a zinc-rich paint is brushed on. Now that stainless steel has taken over most of the duties of galvanised mild steel, the most common galvanised item to be seen on boats is the anchor chain, and probably the anchor too. Be that as it may, zinc-plating is still a powerful defence against rust.

A metal ring or band which holds the bowsprit to the stemhead. A word not much used in recent decades, but as the benefits of bowsprits are re¬discovered, it may come back too. (And see Cranse iron.)

Boarding plank.

In wooden boats, the plank or strake nearest the keel. One each side, of course.

Short lengths of rope or tape used as sail-stops or ties.

A method of starting a race when a large number of boats is involved. The starting line is not static, but lies between a moving boat and a free-floating buoy. (See also Line start.)

The g is soft, but the coat should not be. It is the glossy outer skin of a resinglass moulded hull which not only gives desired beauty but also protects the underlying laminate against ingress of water. It is between half and a quarter of a millimetre in thickness (up to a fiftieth of an inch, say) and should be treated with care. Scratches and cracks should be filled before water gets a chance to penetrate, for a subsequent frost would burst further areas of gel coat away from the laminate. Most of the troubles with resinglass hulls are related to the gel coat.

See Asymmetric spinnaker.

A large triangular headsail, extending abaft the mast and often coming right down to the deck. A very efficient sail, because it gets a clean wind free from interference by any other sail, the ‘genny’ can be awkward to handle and, if low¬cut, can block the helmsman’s view ahead. It was first recognised as a sail in its own right at the 1927 International Regatta in Genoa, though in fact it is simply a development of the Dutchman’sfok, the reaching staysail and the fisherman jib.

An especially lightweight headsail for winds of up to about Force 2 (or between 1 and 2). Would be in cloth of 2 to 3 ozs. To Ghost is to sail very slowly in the lightest of airs. (And see Drifter.)

A clinker-built open boat of four or six oars. Long and lean, she is easy to pull. She may also be rigged with sail. Naval officers go ashore in them and practical civilians sometimes get a chance to buy one that the Navy no longer needs. (Both gs are hard.)

Concentric, pivoted metal rings which allow a compass, lamp, or the like to swing freely and so to remain upright no matter how the ship pitches or rolls. The g is soft and the plural form is used of the device alone, but the singular is used in combination as Gimbal-ring. Used as a verb (or participle for purists) in ‘a gimballed stove’.

Gilded floral or curlicue carvings at a boat’s bow or quarters, or across her stern.

A wheel on a windlass with notched and grooved rim to receive and hold the links of a chain cable.

To constrain or distort a sail by a rope or other hard edge running across it. The hull may be girt by a mooring line or anchor cable.

Globalnaya Navigatsionnaya Sputnikovaya Sistema or Global Navigation Satellite System. Equivalent to GPS, operated by the Russian government.

‘Marine glue’ is not glue at all. It is a special compound used for Paying or caulking the seams between deck planks. Having got that off our chests we are left with a wide range of waterproof adhesives which can be used for boat¬building and on which you can get information from a hardware or tool shop – or even by writing to some magazine editor who has nothing much else to occupy his time …

Global Maritime Distress Safety System. An internationally agreed set of safety procedures, types of equipment, and communication protocols used to increase safety and make it easier to rescue distressed ships, boats and aircraft.

Reverse vang, hence the name. A rigid strut above the gooseneck exerts a downward force on the boom.

Also ‘put about’. To turn the ship’s head through the wind, to tack. Turning the other way, tail to wind, is to Gybe or Wear.

Visibility more than 5 nautical miles

Please see Cutless bearing.

The double-hinged fitting which attaches the boom to the mast.

Running before the wind with mainsail out to one side and staysail to the other. Also Wing and Wing.

Global Positioning System. A highly accurate navigational aid which makes use of automatic measurements from a multiplicity of artificial satellites.

A wind resulting from a difference in barometric pressure across the face of the earth. The more marked the change of pressure in a given distance, or the closer the isobars on the synoptic chart, the steeper the gradient and the higher the resulting wind speed.

A granny knot afloat is the same as ashore, and the same that you learned about in infancy – I hope. It is not a knot at all- just a useless mistake.

A multiple hook, with two, three or four prongs, designed to catch in a bush ashore, or to snare a lost cable on the bottom. If you are thinking of taking up piracy to augment your retirement pension, lay in a good stock for grappling before boarding.

A collection of square holes held together by wood – preferably teak. Ideal for the floor of a shower-room, but shows to its best in the cockpit of a really smart yacht, or in the bottom of her tender. In a perfect world every boat would have gratings.

To inlay a piece of wood so as to make good a damaged part. The inlay is known as a Graving-piece and if fitted by a craftsman you won’t know that it is there.

Please see Rhumb line.

The chemical process of curing a resinglass hull can take days or weeks. Although the resin may appear to have set quite firmly in less than an hour, the assembly may be susceptible to permanent distortion for a period of weeks. If left unsupported during that time. it may take on a permanent change of shape. This is part of the green stage, though the greenest part is in the first hour. Moral: if you buy a freshly moulded hull, set it up true, support it well, and build in stiffen¬ing bulkheads and the like before supports are moved.

Gridded Binary. A data format used in meteorology to store historical and forecast weather data. Often used by sailors to provide weather overlays to charts for routeing.

A small marine creature, similar in appearance to a woodlouse, which eats underwater timber. Unlike the Teredo, it does not burrow into the wood but bores in to about an inch, then emerges and starts again. It thus reveals its presence. Like teredo it dies when the timber is removed from salt water.

A compass which has a movable frame of reference or cursor which can be rotated to any desired setting.Thereafter it is necessary only to maintain a course such that the compass ‘needle’ (or a boldly marked card) remains coincident with the grid marking above. If the grid is correctly set in the first place this arrangement makes it much easier to hold the right course, and errors due to mis-reading are eliminated.

A sailing boat gripes when she shows a strong tendency to turn up into the wind and requires great tiller force to restrain her. The noun Gripe from which it derives means the forefoot or the forward extremity of the keel, but it is now obsolescent.

An eyelet in the edge of a sail, usually a small one such as is used +to attach a luff-slide. Modern sails have grommets at head, tack and clew, but habit has endowed those larger grommets with the name of Cringle. In the past that word was reserved for a ring attached outside the bolt rope, whereas a grom¬met was an eye within the rope, in the margin ofthe cloth itself. The brass eyelets you can fit yourself with a punch and die are grommets aboard ship.

A rope ring. Handy for deck quoits.

Technically, this is a swell which, on reaching a depth of less than half its wave-length, starts to become shorter and steeper, preparatory to breaking in even shallower water. In that sense it is a wave-train which is influenced by the nearness of the ground. But to most yacht skippers, a ground swell is just a swell which arrives from far off when there is no local wind to set up seas of the same height.

Your anchoring equipment, principally your anchors and cables.

An escape route for electrical charge built into the hull of a boat, essential for minimising damage from lightning strikes.

An anchor cable is said to grow in the direction in which it lies from the ship. ‘Which way does the cable grow?’ a good wife should ask her straining husband. If she can understand his reply she should motor the boat slowly in that direction to relieve the load.

Glass-Reinforced Plastic

The ‘fence’ around the deck which should save you from falling over¬board. It should be at least two feet high, and good and strong.

Every book must have its sex interest nowadays, and here it is. The gudgeon is the female part of a pair of rudder hangings, into which the male Pintle fits. You need a pair of these pairs to hang a rudder, and sometimes more may be used.

A type of sail, the upper half of whose luff is fixed to a yard which rises bodily up to the mast and extends more or less vertically above it. The resulting short mast is welcome on dinghies which are left on open moorings, or are trailed on the road, or which are used on waters spanned by low bridges. A jolly good rig for boats up to twenty feet or so, but rare in anything larger. Note that the yard stands almost vertically, in contrast with the acute angle of a Gaff. (See Lug¬sail.)

A wale is a strake standing proud of the planking, and the gunwale should be the uppermost member along each side of a hull, linking all the ribs and the topmost plank. But the usage now has it simply as the upper edge of the ships side, even in resinglass boats where no such structural wale exists. It is pronounced gunnel, as you are perfectly well aware. (Please see Sheer strake, too.)

A rope used to restrain a boom. It may lead forward from the boom as a precaution against an unexpected gybe, or else aft from a Spinnaker boom.

(or jibe in American) To turn a boat so that the wind changes from one quarter to the other across her stern, so swinging the mainsail over abruptly. This manoeuvre is called a gybe. A Gybing course is one where the boat is run¬ning before the wind with a chance that the wind will get behind the mainsail and swing it across. In a cabin boat a deliberate gybe is made by hauling in the main sheet until the sail is almost fore and aft so that it cannot gain much momentum in its short swing across. Once the wind is on the new side of the sail the sheet can be eased. Light dinghies, by contrast, often Gybe all standing, allowing boom and sail to sweep right across from square out on the one side to square out on the other. The greater mass and inertia of gear aboard a cruising boat makes the gybe all standing a risky business. (See Wear, to.)

Helmsman’s warning call to crew members who have just had their hats knocked off by his unpremeditated gybe.

(abbreviation gyro). A non-magnetic means of ascertaining a vessel’s heading by always pointing to true north. Traditionally gyrocompasses used a rapidly spinning wheel, but modern versions often use lasers. Gyros are often used to stabilise autopilot systems.

A graph plotting a boat’s righting moment (expressed in lbs or kg) or righting arm (in ft-lbs or kg-m) from 0° to 180° of heel.