Boat Glossary

Bird Problems on Boats and How to Deal with Them

From masthead to sunpad, practical measures that really help against gull and pigeon invasion — and why the mess needs clearing up straight away.

Boat Electronics Accessories: What’s Essential, What’s a Luxury?

A practical discipline for prioritising purchases against the lure of the electronics catalogue — a realistic shopping list, ordered from safety to comfort.

Compass Variation: What Are Variation and Deviation?

Two separate differences between the compass north and chart north — one caused by the Earth, the other by your own boat.

Engine Cooling Systems: What Are Direct and Indirect Cooling?

The difference between seawater running through the engine itself, or cooling a closed circuit — a design choice that determines how long an engine is likely to last.

Hull Materials: GRP, Timber, Steel, Aluminium

Four answers to what a boat is made of — each material has its own problems, its own maintenance schedule and its own owner profile.

Internet on a Boat: Starlink and Alternatives

From working in a bay to film night, there are three ways to stay connected on board - GSM’s practicality, Starlink’s freedom, and the limits of marina Wi-Fi.

Mooring Lines: Polyester or Nylon?

The material science behind the ropes that hold a boat alongside the quay: stretchy nylon, hard-wearing polyester, and the common enemy of both - a sharp edge.

Outdoor Fabrics: What Are Acrylic and Solution-Dyed?

The fabric science behind canopy and cockpit cushions - the answer to the question, ‘why is this one so much more expensive?’ is solution dyeing.

Parts of a Boat: Cockpit, Cabin, Saloon

From cockpit to galley, the names of the spaces on board - the first set of words you learn when you’re new to boating.

Points of Sail: What Are Close-Hauled, Beam Reach and Running?

The names for the angle between wind and course — the alphabet of sailing and the character of each point of sail.

Rig Types: What Are Sloop, Ketch and Yawl?

The families created by mast count and layout – from the simplicity of a sloop to the flexibility of a ketch, each rig has its own character.

Running Aground: First Actions

A calm, step-by-step protocol for an accident that can happen to anyone — stressing that the first reaction is not 'full astern', but to stop and think.

Sailcloths: What Are Dacron and Laminate?

The answer to what a sail is made from - choosing between Dacron’s durability, laminate’s shape-holding, and membrane’s performance.

Sails in a Bag: What Are a Spinnaker and a Gennaker?

Colourful sails that turn light-wind cruising into a lively sail — the gennaker for the cruising boat, the spinnaker for the racer.

Seasickness and Onboard Precautions

The stomach’s response to the inner ear and the eyes disagreeing — the number one comfort issue on a guest yacht, and one that is largely manageable.

What Are a Bimini and a Sprayhood?

The cockpit sunshade and windscreen - the boat’s hardest-working textile pair, and the first thing that shapes comfort on board.

What Are a Porthole and a Hatch?

The round side window and the opening deck hatch — gateways for light, air and, if neglected, drips.

What Are a Shaft Coupling and Alignment?

The connection that joins the gearbox flange to the propeller shaft — and the adjustment of that joint down to tenths of a millimetre.

What Are a Tender and Davit?

The yacht’s small service boat and the gear that carries it — the bay-life runabout and one of the most stolen, most neglected bits of kit.

What Are AGM and Gel Batteries?

Two maintenance-free sealed lead-acid battery families — the answer to ‘which one?’ lies in the usage profile.

What Are Amp-Hours (Ah) and Battery Capacity?

The unit used to measure a battery’s energy store - knowing that only half the number on the label is truly usable is the first step in energy planning.

What Are Blocks and Tackles?

The silent physics behind every rope on deck: blocks that change direction and tackles that multiply power.

What Are Boat Cleaning Chemicals?

A guide to the jobs different boat chemicals do, from acids to alkalis - a compass for a job where the wrong product does more damage to the surface than it does to the dirt.

What Are Boat Security Systems?

Layered protection for the valuables aboard, from outboards to electronics: deter, delay, and detect.

What Are Bow, Stern, Port and Starboard?

The names of a boat’s four main directions — the shared language that replaces ‘left and right’ at sea, helping to avoid confusion and accidents.

What Are COG and SOG?

Your GPS’s true course and true speed — and how they differ from the compass and speed log, showing the effect of current.

What Are Cradles and Stands?

The blocks and support arrangement that carries a boat ashore — the least talked-about bit of engineering, yet the one that takes the full weight all winter.

What Are Day Shapes?

Black balls and cones hoisted on the mast - the international daytime language for saying 'what I'm doing', and the small rule most often forgotten.

What Are Displacement and Planing Hulls?

The basic divide between a boat that parts the water and one that rides over it — and the DNA of speed, fuel burn and comfort.

What Are Engine Belts (V and Poly-V)?

Rubber belt transferring drive from the crank pulley to the alternator and pumps - the part that takes charging, and on many engines cooling, with it the moment it snaps.

What Are EPIRB and PLB?

Transmitters that send an identified distress signal via satellite — the last layer of safety once VHF range has run out.

What Are Epoxy and Polyester Resins?

Two core chemicals in yacht building and repair — production starts with polyester, while lasting repairs are usually done with epoxy.

What Are Genoa and Jib?

The family of sails set forward of the mast — the larger one is called a genoa, the smaller one a jib; the numbers show the difference between them.

What Are Lazy Jacks and a Lazy Bag?

A rope web that guides the mainsail onto the boom, and the zipped bag that waits for it — standard comfort for working the main with a small crew.

What Are Lifejackets and Safety Harnesses?

A lifejacket keeps you afloat if you go overboard, while a harness-and-line arrangement stops the fall in the first place — two separate, complementary layers of personal safety.

What Are Lighthouse Characteristics?

Each lighthouse has its own light rhythm - the language behind the chart code ‘Fl(2) 10s’ that tells you which light it is at night.

What Are LOA and LWL?

Two different ‘lengths’ for a boat: the overall length that drives charges, and the waterline length that drives performance.

What Are Lodos and Poyraz?

The warm, lively south-westerly lodos and the hard, dry north-easterly poyraz - two defining winds of the Turkish coast, and two very different preparation lists.

What Are Nautical Miles and Knots?

The sea has its own kilometre and its own clock - a system of measurement that combines chart work with maths, which is why it never retires.

What Are Navigation Lights?

A boat’s ID card at night at sea - the art of reading who is going where by red, green and white lights.

What Are Shackles and Swivels?

Small metal links that connect the anchor to the chain - proof that the whole ground tackle is only as strong as its smallest part.

What Are Signal Flares?

Parachute, hand-held and smoke pyrotechnics — the last layer that still delivers that 'they've seen me' moment, even in the electronic age.

What Are Sound Signals (Whistle Rules)?

One short for “I am altering course to starboard”, five short for “I do not understand your intentions” - the universal language of the whistle, and the key fact that the five short blast is the most important of all.

What Are Stays, Forestays and Shrouds?

Steel wires that hold the mast up from fore, aft and sideways — if even one gives way, the mast can come down.

What Are Tacking and Gybing?

Two ways to take the wind onto the other board — a tack turns the bow through the wind calmly, while a gybe brings the stern round and demands discipline.

What Are the Basic Seaman’s Knots?

Five knots that genuinely matter on a boat out of the hundreds there are - each one solves a real job, and all can be learnt in ten minutes.

What Are the Different Types of Anchor?

From ploughs to next-gen designs, there is no single 'best anchor' - only the right anchor for the seabed and the boat.

What Are the Flag Rules on a Boat?

From the ensign at the stern to the courtesy flag in a foreign port - the most visible set of rules afloat.

What Are True Wind and Apparent Wind?

The story of the wind measured by a stationary observer versus the wind felt by a moving boat — and which one the sails are really working with.

What Are VHF Radio and DSC?

The phone and distress button at sea - a life-saver where mobile signal drops out, and often the more reliable option even where it does work.

What Are Wave Height and Period?

A note explaining that a forecast ‘1 metre wave’ says very little on its own, and that period is what really determines comfort.

What Does Boat Ownership Cost Per Year?

The purchase price is only the entry ticket - the annual ownership budget lines and the ones most often forgotten.

What Is a Barometer?

A classic instrument for measuring atmospheric pressure — the old hand that answers ‘will the weather turn?’ even in a bay with no signal.

What Is a Battery Charger (Marine Charger)?

The smart unit that turns shore power into the language of your batteries - responsible for keeping them alive through lay-up and bringing them up quickly in summer.

What Is a Bearing?

A measure of which compass direction an object lies from you in — even in the GPS age, still the most reliable eye for spotting collision risk.

What Is a Bilge Float Switch (Automatic Float Switch)?

A level switch that starts the pump when water rises in the bilge — the cheapest, yet one of the most vital, electrical parts on board.

What Is a Bilge Pump?

The pump that throws water out of the bilge - the bit everyone assumes they have, everyone overstates the capacity of, and the one-minute test that can save a boat.

What Is a Blue Card?

An electronic card recording a boat’s waste disposal history - the administrative tool that helps protect Göcek’s waters and the first thing checked in inspections.

What Is a BMS (Battery Management System)?

An electronic watchdog that monitors and protects every cell in a lithium battery - the very thing that makes lithium safe.

What Is a Boat Cover (Winter Cover)?

A cover that protects the wintering boat from sun, rain and dirt - get it right and it protects the gelcoat; get it wrong and it becomes a mould and abrasion machine.

What Is a Boat Electrical Panel?

The panel where all the boat’s circuit breakers and fuses are gathered — tidy and it helps you find faults, messy and it becomes the fault.

What Is a Boat Trailer?

The road-going legs of a small boat - the gear that gives a boat freedom with the right trailer, correct securing, and good launch-ramp technique.

What Is a Boat Transfer (Delivery)?

Having a professional crew move the boat on the owner’s behalf — the unseen logistics behind post-purchase handover and seasonal port changes.

What Is a Boat’s Tonnage (Gross and Net Ton)?

Most “tons” in paperwork are not weight but volume — knowing the difference between gross ton, net ton and displacement is how you make sense of the documents.

What Is a Bollard?

A twin-arm metal fitting used to secure a line to the boat - one of the first pieces anyone who knows mooring learns about.

What Is a Bonding System?

A network that links the underwater metals — seacocks, shaft, rudder — with heavy conductors and to the anode, the unseen layer of corrosion defence.

What Is a Boom?

The horizontal spar that carries the foot of the mainsail - the boat’s busiest, and in the cockpit the most dangerous, piece of metal.

What Is a Bow Thruster?

A tunnel thruster that produces sideways thrust through the hull near the bow - the bit of kit that gets the most thanks in tight marinas and the least maintenance.

What Is a Bulkhead?

Structural panels that divide the boat across the beam, often looking like joinery but in fact carrying the hull shape and mast loads as part of the internal frame.

What Is a Catamaran?

Two hulls, a wide, stable boat - the new standard in comfort, but a maintenance world where everything comes in pairs.

What Is a Chartplotter?

A navigation computer that plots GPS position on an electronic chart — the screen where all the boat's sensors meet, and the answer to the question: 'won't a tablet do?'

What Is a Check Valve?

A small valve that only lets liquid flow one way — the bilge line’s best friend and its hidden suspect.

What Is a Compression Test?

A test that measures each cylinder's compression pressure - the clearest way to assess an engine's internal health without taking it apart.

What Is a DC-DC Charger (B2B)?

An intermediary charger that takes power from the starter battery line and feeds the service bank with the correct charging profile — a peace deal for mixed battery chemistries.

What Is a Deckwash Pump?

A pressurised water line for washing down the deck — the cure for anchor mud and fish day mess, and a friend to your fresh-water tank.

What Is a Diesel Heater (Webasto Type)?

A compact diesel stove that heats the cabins with very little fuel — a device that extends the season and, when run on a low tick-over, quickly rewards itself with soot.

What Is a Diver Check?

An underwater inspection and clean carried out while the boat is afloat - the eyes between haul-outs, and the remedy for mid-season performance loss.

What Is a Fender?

The inflatable buffer between a boat and the quay/another boat — the cheapest but most commonly misused part of the mooring set-up.

What Is a Flybridge?

An open command and living deck above the cabin - better all-round visibility when manoeuvring, a second lounge in season, and an extra maintenance item in winter.

What Is a Freshwater Pressure Pump?

An automatic pump that delivers fresh water from the tank to the taps under pressure - the onboard equivalent of domestic mains-water comfort.

What Is a Freshwater Tank and How Is It Maintained?

The boat’s potable and domestic water tank — the source of the “water smells bad” complaint, and a problem solved by one day’s maintenance each year.

What Is a Fuel Pre-Filter (Water Separator)?

A clear-bowl filter that strips water and sediment from diesel before it reaches the engine - the watchkeeper that catches tank problems before they get that far.

What Is a Galvanic Isolator?

A protective device that stops galvanic current coming in via shore power earth — the silent guardian of a yacht on the marina berth.

What Is a Gas and CO Alarm?

Sensors that pick up LPG leaks and carbon monoxide before anyone notices - if the battery and service life aren’t tracked, they’re just plastic boxes.

What Is a GRIB File?

A data format that shows raw weather model output on a map with arrows - the behind-the-scenes engine of forecast apps, and a way to get weather with limited internet.

What Is a Guardrail/Stanchion System?

The stanchions and wire lifelines around the deck - the last physical barrier against a fall overboard, and the bit of safety kit most often forgotten when it comes to maintenance.

What Is a Gulet?

An Aegean classic with a broad transom and wooden hull — the emblem of blue cruising and the ultimate test of disciplined timber maintenance.

What Is a Halyard?

The line that hoists and tensions the sail on the mast — only touched a few times a season, yet the wrong tension is felt on every passage.

What Is a Heat Exchanger?

A tube bundle that cools the engine’s fresh-water circuit with seawater — the marine equivalent of a car radiator.

What Is a Holding Tank?

A tank that stores toilet waste until it can be handed in at a shore station - the key piece of kit in protected areas where discharge to sea is banned.

What Is a Hydraulic Steering System?

A system that carries the helm’s movement to the steering ram using hydraulic pressure — quiet and effortless, but it will not forgive air in the circuit.

What Is a Hydraulic Stern Platform?

A submerging, load-bearing stern platform — tender ramp, beach mode and step-free access to the sea all in one.

What Is a Keel?

The ballast-filled foil beneath a sailing boat’s hull - the balancing element that counters heel and one of the most commonly overlooked inspection points.

What Is a Kill Switch (Safety Lanyard)?

A pull-cord that stops the engine instantly if the helm leaves the driver - the cheapest, most neglected life insurance on a small boat or tender.

What Is a Kotra?

A word with two lives in Turkish - in everyday speech, ‘any sailboat’; in technical terms, a classic single-masted yacht type.

What Is a Liferaft?

The inflatable refuge in a boat-abandonment moment - carried for years without ever being opened, but effectively useless once the service date has passed.

What Is a Line Clutch?

A lever-operated device with toothed jaws that locks a line under load - the key to one winch serving several lines.

What Is a Logbook?

The written record of a yacht’s passages and condition — part seafaring tradition, part fault-finding tool, and often the most valuable document on sale day.

What Is a Macerator Pump?

An electric pump that grinds waste so it can be pushed through a small-diameter hose - the hardest-worked, shortest-lived component in the waste system.

What Is a Marina Contract?

The legal framework for annual berthing - from what the fee covers to who is liable in storm damage, and what to read before signing.

What Is a Marine Diesel Turbo?

A turbine driven by exhaust gases that forces extra air into the engine - a force multiplier, but often the first casualty on boats run at idle.

What Is a Marine Fridge?

A 12V compressor fridge on board - often the biggest item in the energy budget, and one whose consumption can be halved with a few simple habits.

What Is a Marine Gearbox?

The gearbox that turns engine rotation into ahead-astern-neutral and reduces revs - little talked about, expensive when it fails, but straightforward to maintain.

What Is a Marine Generator?

A small diesel power plant on board producing 220V - the heart of a comfortable, air-conditioned boat, but also the grumpiest bit of kit if it is not run often enough.

What Is a Marine Toilet?

A seawater-flush toilet - often the boat's most troublesome system, but one of the least problematic if the rules are followed.

What Is a Marine Water Heater?

The boat’s hot water tank - a unit that runs on both 220V immersion heat and the engine’s waste heat, delivering a ‘free shower’ on passage days.

What Is a Moisture Meter Reading?

A scan taken with a meter that reads moisture in the laminate from the surface - a measurement that takes the guesswork out of osmosis and balsa rot discussions.

What Is a Mooring Line?

A ready-made berth setup that holds the bow in place on a concrete block on the seabed — the unseen infrastructure behind Mediterranean stern-to berthing without an anchor.

What Is a Morse Control Cable?

The steel-cored cable that carries the control lever’s movement to the engine - a part that stiffens over the years and always seems to fail at the worst possible moment.

What Is a Motorsailer?

A hybrid that carries a serious engine and proper sailing rig in the same hull — the boat for those who say “compromise on neither” and those who want “the best of both worlds”.

What Is a Nautical Chart?

The official language of depths, dangers and marks - a document that still pays to know how to read, even in the age of chartplotters.

What Is a Passarelle?

The gangway between the yacht and the quay - the essential comfort of Mediterranean stern-to mooring and the first test of guest safety.

What Is a Remote Boat Monitoring System?

A sensor-and-network setup that puts your boat’s position, battery and bilge in your pocket — the technological answer to “what state is the boat in, I wonder?”

What Is a RIB (Rigid Inflatable Boat)?

A marriage of fibreglass hull and inflatable tubes - light on weight, heavy on seaworthiness, a highly versatile craft that bridges the gap from tender to fast workboat.

What Is a Sail Drive?

A system that transfers the engine’s power to the propeller through a leg that runs straight down through the hull - the standard on modern yachts, with two critical maintenance points.

What Is a Sandwich Hull?

A structure with a light core (balsa/foam) sandwiched between two fibreglass skins - the secret to stiffness and low weight, and the hiding place of the most insidious problem if water gets in.

What Is a Scupper?

Drain openings that send deck water back overboard — when they block, they can turn the cockpit into a bath, making them one of the cheapest but most critical bits of maintenance.

What Is a Seacock (Kinistin)?

The gate to every seawater inlet and outlet below the hull — a valve left unused is a valve that will fail when you need it most.

What Is a Seawater Strainer?

A clear-cased filter fitted on the seawater intake line, screening out weed and debris before they reach the impeller and heat exchanger.

What Is a Shaft Seal (Stuffing Box)?

The sealing arrangement where the propeller shaft exits the boat — the most deliberately designed 'controlled hole' on board.

What Is a Sheet?

The line that sets the sail’s angle to the wind — the real boating equivalent of a ‘throttle pedal’ analogy.

What Is a Shunt and Battery Monitor?

A measuring shunt and display that count every amp in and out of the battery — answering “how full is the battery?” with figures, not guesses.

What Is a Spring Line?

Cross lines that stop a boat creeping fore and aft along the berth — the difference between a mooring that just holds and one that holds properly.

What Is a Squall?

A sudden, sharp burst of wind under a dark cloud — a few minutes can take you from 15 knots to 35, but a well-prepared boat will ride it out with no fuss.

What Is a Stabiliser (Roll Dampener)?

A family of systems that cuts roll at anchor and under way - from gyro stabilisers to a simple bilge keel, a comfort problem and the technology ladder that tackles it.

What Is a Starter Motor?

A heavy-duty electric motor that takes a high current from the battery to turn the engine over first — the chief suspect behind the ‘click’ and a silent morning.

What Is a Steering System?

A steering system made up of the rudder blade, stock and bearings - the one piece of equipment a boat truly cannot do without, and a key item on any haul-out inspection.

What Is a Stern Drive?

A system that transfers the engine’s power from inside the boat to the moving drive unit on the transom — the standard for sports boats, and a real test for bellows maintenance.

What Is a Thermostat?

An automatic valve that keeps engine operating temperature steady - when it fails, the symptom can be not just overheating, but also ‘never warming up’.

What Is a Tirhandil?

A balanced, seamanlike Aegean classic with a sharp bow and stern - long overshadowed by the gulet, now gaining collector value for its wooden elegance.

What Is a Transducer?

A sensor that sends sound waves into the water and listens for the echo - the source behind the depth reading on your display.

What Is a Transit Log?

The document granting a foreign-flagged yacht permission to cruise in Turkish waters — with validity, port and crew/passenger details to be tracked.

What Is a Transom?

The aft closing wall of the boat - the structure that carries the full load of an outboard engine, and quietly rots away if water gets into it.

What Is a Travel Lift?

A mobile crane that lifts the boat from the water with web slings passed underneath — the main machine on haul-out day and the one that answers the question, ‘where do the slings go?’

What Is a Traveller (Track Car)?

The transverse track that moves the mainsheet traveller car side to side - the least understood trim control, letting you change sail angle without touching the mainsheet.

What Is a Trawler?

A displacement motor yacht with fishing-boat roots: slow-going, long-legged and frugal with fuel - a boat for people in no rush.

What Is a Trim Flap?

Adjustable plates under the transom that push the bow down and help the boat onto the plane faster, with a direct effect on fuel burn and comfort.

What Is a Vang (Boom Vang)?

A tackle or piston that pulls the boom down — the control on open reaches and runs that keeps the sail set; on many boats it is never touched.

What Is a Waterlock (Silencer) in the Exhaust System?

A water trap in the exhaust line – it looks like a silencer, but its real job is to stop seawater and exhaust water running back into the engine.

What Is a Watermaker?

A machine that turns seawater into fresh water by forcing it through a membrane at high pressure - the freedom of longer passages, for the kit that sulks when left idle.

What Is a Winch?

The drum that reduces rope loads through gearing to human strength — the cockpit’s muscle system and the one fitting that deserves to be opened once a year.

What Is a Wind Generator?

A small wind turbine fitted to the stern mast: the only source that can keep producing at night, but if the expectations are wrong it quickly becomes a noisy disappointment.

What Is a Windlass?

The deck winch that lowers and raises the anchor and chain - the heart of anchoring comfort, and a real test for high current and salt.

What is AIS?

A system that broadcasts a vessel’s identity, position and course to other vessels over VHF - the most valuable second pair of eyes at night and in fog.

What Is an Alternator?

An engine-driven generator that charges the batteries while motoring - the boat’s only power station underway.

What Is an Anchor Alarm?

A GPS watchkeeper that tells you when the boat has moved outside its anchor circle - the cheapest insurance for a night at anchor, if set up properly.

What Is an Autopilot?

An electronic helmsman that keeps the vessel on the set course — the most valuable crew member on a long passage, but never a watchkeeper.

What Is an Electric or Hybrid Boat?

A propulsion system powered by batteries, or combining diesel with electric: where the appeal of silence meets the reality of range — a great choice with the right expectations.

What Is an Emergency Leak Kit (Plug Kit)?

A small grab-bag of conical plugs, emergency sealant and hose clamps - the kit that buys you the first 60 seconds when the boat starts taking water.

What Is an Emergency Tiller?

The direct-fit emergency steering arm that goes straight onto the rudder stock when the wheel system fails — standard kit on every boat, but actually tried on very few.

What Is an Engine Mount (Mushroom Mount)?

Rubber-mounted feet that connect the engine to the hull - both a vibration-absorbing cushion and the millimetre reference for shaft alignment.

What Is an Exhaust Elbow (Mixing Elbow)?

The elbow where exhaust gases meet cooling water - one of the sneakiest, most overlooked wear items on marine engines.

What Is an Impeller?

The flexible rubber impeller in the seawater pump - the smallest but most critical link in the engine cooling chain.

What Is an Injector?

A precision valve that sprays fuel into the cylinder at high pressure and exactly on time - the engine’s guardian at the sharp end of performance.

What Is an Inverter?

A unit that turns 12/24V DC from the batteries into 220V shore power — the source of comfort at anchor, or battery carnage if you size it wrong.

What Is an Isolation Transformer?

A transformer that transfers shore power to the boat without a direct physical link, using a magnetic field - the complete cure for galvanic corrosion and stray current issues.

What Is an LPG (Calor Gas) System on Board?

The bottled gas arrangement that feeds the galley cooker - the rules and small but vital fittings that let you live safely with a heavier-than-air gas on board.

What Is an MPPT Charge Controller?

A smart controller that converts a solar panel’s output into battery-friendly power — the difference that can squeeze noticeably more amps from the same panel.

What Is an Outboard Motor?

A complete power unit hung on the transom - the heart of small boats and tenders, a motor that lives well in salt water but still likes a fresh-water rinse.

What Is Anchor Dragging?

When the anchor breaks out of the seabed and the boat starts to drift — the one real emergency for a boat at anchor, and almost always preventable.

What Is Boat Valuation?

Working out a boat’s true market value — where asking prices rely on sentiment, and valuation is driven by data.

What Is Boat Vinyl Wrapping?

A coloured adhesive film applied to the hull - a quick way to change colour without paint, with the added bonus that it also protects the gelcoat.

What Is Cavitation?

The collapse of vapour bubbles formed by a drop in pressure around the propeller — a silent abrasive that can even eat into metal.

What Is Ceramic Coating on a Boat?

A hard protective layer that chemically bonds to gelcoat - a modern option that lasts for years, not just the few months of a traditional wax.

What Is Cruising RPM?

The rev range where the engine works efficiently and comfortably - the point where fuel, noise and engine life all win at once.

What Is Diesel Bug?

A colony of micro-organisms breeding at the fuel tank’s water-diesel interface — the silent saboteur of an underused yacht.

What Is Draft?

The distance from the waterline to the lowest point of the keel – the only real answer to ‘can I get in there?’

What Is Electrolysis? (Common Term)

The common catch-all for any underwater metal wasting away in a marina — an editorial note explaining that two different problems usually sit behind it: galvanic corrosion and stray current.

What Is Engine Hours?

The engine’s total running time — the boat’s ‘mileage’, but the figure most likely to mislead if read on its own.

What Is Fire Safety On Board?

From handheld extinguishers to an engine-room automatic system — a defence set-up built around the fact that no fire brigade is coming at sea.

What Is Fog Navigation?

A survival routine at sea when visibility drops to a few hundred metres - slow down, make sound, and keep radar, AIS and your ears working together.

What Is Fouling?

The build-up of weed, mussels and barnacle growth on the hull — a living load that quietly taxes speed, fuel and engine health.

What Is Freeboard?

The height from the waterline to the deck edge — the boat’s visible ‘dry margin’ against the sea and a clear sign of loading discipline.

What Is Fuel Consumption Calculation?

The real maths of a boat’s fuel use — once you start thinking in miles rather than hours, consumption and range become much clearer.

What Is Furling?

A drum-and-profile arrangement that rolls the sail away with a pull on a line — the bit that makes short-handed sailing possible, and the one most often left until the last minute on maintenance.

What Is Gelcoat?

The outer coloured protective skin of a polyester boat — not paint, but a layer formed in the mould with the hull.

What Is Jet Propulsion?

A propeller-free system that draws in water and jets it out under pressure — kinder to shallow water and swimmer safety, and an enemy of weed.

What Is Marine Air Conditioning?

A compact air-conditioning system that dumps heat into seawater; unlike a house unit, it lives with the sea, and most faults happen on the water side.

What Is Marine Antifreeze?

A story of two antifreezes, two different jobs — and why the pink liquid used to winterise water systems must never be confused with the chemistry in the engine’s closed circuit.

What Is Marine Cable and Wire Size?

Tinned-copper, multi-strand specialist cable — the unseen quality behind boat electrics and the subject of voltage-drop calculations.

What Is Marine Engine Oil?

A short, practical guide to choosing oil for a marine engine — from viscosity numbers to change intervals.

What Is Marine Mastic (Sikaflex)?

The chemistry behind every sealing and flexible bonding job on a boat — a clear guide to “which tube goes where?”

What Is Marine Radar?

A sensor that maps the surroundings by the echo of radio waves — the one eye that sees non-broadcast targets AIS cannot detect, such as dinghies, buoys and squalls.

What Is MOB (Man Overboard)?

The most time-critical emergency in sailing - a procedure where the three reactions in the first five seconds decide everything that follows.

What Is Moisture and Mould Management on Board?

The hidden enemy in a closed yacht is condensation – from under the cushions to the corners of lockers, ways to stop the cabin from falling prey to mould.

What is NAVTEX?

A receiver that automatically picks up written bulletins from coast stations — a system that puts storm warnings and navigation notices in your pocket without the internet.

What Is Oil Analysis?

Laboratory analysis of used engine oil - a powerful, little-known marine diagnostic that reads wear inside the engine without opening it.

What Is Osmosis?

Water seeping beneath the gelcoat and forming acidic pockets in the laminate - the hull problem everyone fears, and most often misdiagnosed.

What Is POD Drive (IPS)?

Independent rotating drive units beneath the hull and joystick control - a technology that turns marina manoeuvring into child’s play, but demands strict adherence to the maintenance schedule.

What Is Posidonia (Seagrass)?

The dark green meadows at the bottom of the bays — the Mediterranean’s oxygen factory, keeper of clear water, and a forest you must protect when anchoring.

What Is Propeller Pitch?

The theoretical distance a propeller would travel in one turn — the figure that shows whether the engine can reach its correct rpm.

What Is Reefing?

The staged reduction of a mainsail - with the universal answer to “when should you reef?”: as soon as it first occurs to you.

What Is Right of Way at Sea (Collision Avoidance)?

A boat owner’s plain-English summary of the international collision-avoidance rules — and the key fact that the main rule is ‘don’t collide’, not ‘be right’.

What Is Scope?

The length of chain paid out when anchoring - more often than not, this figure decides whether the anchor holds rather than the anchor itself.

What is Shore Power?

220V shore electricity from the marina to the boat - a source of comfort, but also of corrosion and risk if it is installed incorrectly.

What Is Stainless Steel Maintenance?

The science behind brown marks on guardrails and fittings - why stainless steel is really ‘stain-resistant’ and stays bright with proper care.

What Is Stern-to-Shore Mooring (Mooring Buoy Mooring)?

Bow to anchor, stern lines to shore — the standard arrangement in Göcek bays, and the method that makes room for everyone in a busy anchorage.

What Is Stray Current?

An emergency fault where current leaking from the DC system into the water rapidly eats away at metal — doing in months what galvanic corrosion takes years to do.

What Is Synthetic Teak?

A PVC/composite deck covering that mimics real teak — a modern lower-maintenance option, with a note on hot surfaces and a balanced comparison.

What Is the Amateur Seafarer Certificate (ADB)?

The official qualification for taking the helm of a private boat - one day to sit the exam, a lifetime of responsibility.

What Is the Battery Master Switch?

A rotary switch that cuts the boat’s battery connection in one move — both a safety isolator and, if used wrongly, an alternator killer.

What Is the Beaufort Scale?

The universal 0–12 scale for wind strength — knowing the answer to “how many Beaufort?” is what lets you plan at sea.

What Is the Bilge?

The lowest internal void in the boat - where every leak ends up, and the place that tells you, every day, how healthy the boat really is.

What Is the CE Design Category?

The A-B-C-D letter that shows which sea and wind conditions the boat was designed for - the one letter most often overlooked when buying.

What Is the Hull Below the Waterline?

The hull surface below the waterline — easy to neglect because you can’t see it, but the real driver of performance and fuel burn.

What Is the IALA Buoyage System?

The international buoyage language for marking channels, shoals and hazards – the standard answer to the question, 'Which side do I pass on?'

What Is the Meltem?

The Gulf of Morbihan? no, Ege summer’s clockwork thermal wind — calm in the morning, stronger in the afternoon; a friend to those who plan around it, a surprise to those who don’t.

What Is the Short Range Radio Licence (KMT/SRC)?

The certificate for lawful, correct use of a VHF marine radio — its real value is that it properly teaches the distress-calling procedure, just once, but properly.

What Is the Spare Parts List on Board?

The boxed-up version of the fact that there is no shop in the middle of the sea — which spares to carry, and the minimum and ideal lists.

What Is the Topsides?

The part of the hull above the waterline - the boat’s ‘face’ and the first point of contact alongside the berth.

What Is Towing at Sea?

The technique and etiquette of moving a disabled boat to harbour - from where the towline is secured to the talk about a 'salvage fee', everything you need to know.

What Is Twin-Engine Manoeuvring?

The art of turning a boat on the spot using the two engines separately — the secret to marina manoeuvres with barely a touch on the helm.

What Is Ultrasonic Antifouling?

A system that emits ultrasonic vibrations through transducers bonded to the hull — a promising aid to paint, but not a miracle cure on its own.

What Is Varnish Maintenance?

A clear film that protects timber from UV and water - a living, layered finish that has to be kept up, or you pay for it with sanding later.