Glossary ­ not comprehensive (and it will be added to) but if there's anything on this site or in your report which you don't understand, get in touch.

Beam shelf - on a wooden boat the timber that runs around the inside of the hull beneath the deck edge which supports the beams.

Calorifier - an insulated water tank through which hot seawater from the engine is piped via a coil, transferring part of its heat to the cold fresh water within the tank. They usually also have a 240v electrical immersion heater which can be plugged in to the shore supply when alongside.

Cathodic protection - lumps of zinc (in seawater), magnesium ( in freshwater) or aluminium ( in brackish water) which can be attached to the hull, rudder, stern shaft or outdrives. The idea is that these can erode and be replaced instead of expensive metal under water fittings such as propellers or skin fittings. To do this they have to be electrically bonded and reasonably close to the things they are supposed to protect.

Coach roof - any raised structure on the deck which allows greater headroom below.

Copper nails and roves - square section copper nails hammered through pilot holes and then drawn tight by riveting them over copper washers or roves.

DZR brass - dezincification resistant brass, often used now used to replace bronze in through hull fittings. They usually have a ball valve which turns within a nylon bearing.

Eberspacher diesel heater - the most common form of heating system on small boats where a fan forces air over an element, within which is an electrically ignited diesel burner, and from there to the cabin.

Electrolytic decay - of wood, refers to the break down of wood cells by an electrical current. In a wooden boat if there is copper or copper alloys (e.g. bronze) and iron then there will be an electrical potential between the two metals. Wood that is saturated with seawater will allow a small current to flow which, over years, will cause the wood to decay.

There are other forms of wood decay ­ wet or dry rot from the many different types of mould spore often occurs where rainwater can get in and the wood can not dry out or ventilate. Some softwoods will simply collapse if they become saturated and the cell walls burst. Boats kept up muddy creeks can get infested with gribble (a wood borer). However all of these things take time to develop and can be prevented or stopped.

Epoxy resins - created a breakthrough in wooden boatbuilding ­ they allow wood to be encapsulated (no moisture = no rot), mixed with various powders they make a waterproof glue that sticks to virtually anything and mixed into a stiff paste they make a filler that is far quicker to apply than the traditional method of cutting in 'graving' pieces of replacement wood. They are expensive and a potential cause of allergies (they contain organic peroxides). The most popular brand is 'West' which comes in a two pack kit. A clear resin is mixed 5 parts to 1 with a yellow hardener resin and then filler powders or even fine sawdust added to get the desired thickness. Neat resin can be used to harden up softened wood.

Frames - on a wooden boat, the transverse members, either steam bent or sawn timbers, which support the planking. On older GRP boats, the same purpose is served by plywood bulkheads or half bulkheads which are glassed in to the hull. Newer GRP boats have internal mouldings which glued into the hull.

Ground tackle - general term for the anchor, its chain, any cable, possibly a spare anchor. Anchors can be a Bruce design (like a three pronged rounded shovel), a CQR or plough shape, a Danforth (two trailer prongs all of which folds flat) or a fisherman which is the classic anchor shape.

Heads - compartment or space for a sea toilet.

Hook scarph - a stepped joint used to allow straight grained of the timber to follow the shape of a frame or other supporting structure. Also used to create a long lengths where only short lengths of timber are available.

Insurance survey - a survey required by insurance companies on boats over 10 years old, wooden boats or anything else they may want reassurance upon. Usually presented as an abridged form of a condition survey. It will not cover cosmetic or non-safety related items.

Keel ­ The main centreline timber on a wooden boat, can also refer to a cast-iron or lead ballast keel, particularly on GRP boats.

Laminate - general term for GRP ( glass reinforced plastic), named because layers of glass are bonded or laminated with polyester resins within a mould to create the hull or the deck. Resins can be polyester or epoxy. The latter are far stronger and far more expensive. Polyester resins used to be orthophalic types up to the early 90s. These tended to absorb more moisture than the later isophthalic types. Vinylester resins are even more moisture resistant and often used for gelcoats.

Osmosis - process by which water molecules move through the gel coat and, over time, combine with fibreglass chemicals within existing voids or air bubbles to form pressurised blisters. Build quality is everything; poorly made hulls will have numerous voids in the laminate or bubbles in the gel coat which allow the osmosis to begin. The blisters will eventually burst, exuding an acidic fluid or solute and exposing the underlying laminate. The process does not cause the hull to absorb any significant quantity of water or go 'spongy' and it can take years, even up to the useful life of the boat, to advance to a stage at which the hull is significantly weakened. In short, for most boats osmosis is a cosmetic problem that makes them difficult to sell rather than a danger to sail.

Pulpit - is the stainless steel handrail at the front of the boat . Pushpit is the same thing on the back of the boat . Stanchions are the upright posts around the side of the boat which are fitted with guard wires to cover all other eventualities. Failing all else, most well set up sailing yachts will have a jack stay which is a length of webbing or wire which runs along the deck to which the crew can snap on their safety harnesses.

Rudder types - can be balanced or semi-balanced which means part of the area of the blade is forward of its pivot point. A spade rudder is one which is partially supported or unsupported beneath the hull, the alternative being a transom or skeg hung rudder which pivots on pintles (spikes) and gudgeons (holes for the spikes). A spade rudder is attached to a rudder stock which will go through a hull gland to keep the water out and is controlled by a tiller or by a wheel. If the latter, there will be a quadrant on the top of the rudder stock to which wires are fixed or a tiller arm to which a hydraulic ram or cable steering is attached.

Sandwich or cored deck - used on virtually all GRP decks, two panels of solid GRP separated by and bonded to a core made of end grained balsa wood or foam. The point to check is that the three layers have not become de-bonded due to holes in the deck allowing water in which will cause them to separate.

Skin fittings - usually refers to any hole through the hull to allow seawater in (e.g. for engine cooling) or waste water out. These must be fitted with a sea cock if beneath the waterline so that they can be closed.

Stern gear - general term for the propeller, the propeller shaft and any supporting brackets or bearings.

Topsides - the hull from the waterline to the edge of the deck.

Windlass - mounted on the foredeck to hoist the anchor as opposed to winches which are mounted around the cockpit or on the mast to hoist the sails.

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