A · B · C · D · F · G · H · I · K · L · M · N · O · P · R · S · T · U · V · W · Z
A
ABYC
American Boat and Yacht Council, publishes technical standards for boat systems.
Surveys reference ABYC (notably E-11 electrical, H-27 fuel) and ISO standards.
Antifouling
Coating applied below the waterline to prevent growth.
Thick, multi-layered coatings distort moisture readings; their condition is recorded before measurement.
B
Blister map
A drawing recording the position and density of blisters on the hull.
The only way to see, at the next survey, whether anything has progressed. One set of readings cannot tell you osmosis is advancing.
Bilge
The lowest internal space, where leaks collect.
A dry bilge is a sign of care. Salt traces, rust staining and an oil film each say which fluid came from where.
Blow-by test
Measuring how much combustion gas escapes into the crankcase.
An indicator of ring and bore wear, read together with the compression test.
Borescope
A camera probe for spaces that cannot be reached.
Used inside cylinders, fuel tanks, masts and cored deck voids.
Battery tester
Measures real capacity under cranking load.
Voltage alone does not show battery health; behaviour under load does.
C
Cored construction
Hull or deck built with balsa, foam or honeycomb between two laminate skins.
Light and stiff, but water in the core spreads and rots it. Deck hardware penetrations are the usual entry point; moisture meter and sounding are used together.
Cathodic protection
The system protecting a metal hull from corrosion by anodes or an impressed current.
Until measured, it is an assumption. Stray current tracing on a pontoon concerns every boat on it.
Chainplate
The metal plate anchoring the standing rigging to the hull.
Salt traces around it and damp deck core indicate a leak. In stainless steel, crevice corrosion develops out of sight in oxygen-starved joints.
Compression test
Measuring cylinder pressures.
More than ten per cent below the others in one cylinder points to rings or valves.
Cooling circuit
The raw water and fresh water cooling system.
Blocked heat exchangers, worn impellers and salt deposits are the common findings. Overheating events can often be read from the engine management system.
CE / RCD
The European directive and conformity mark governing boats placed on the market.
On the second-hand market the CE plate, owner's manual and declaration of conformity affect saleability.
Condition survey
A periodic inspection an owner commissions for their own information.
Charter fleets run them at the start and end of the season; they let the maintenance budget be planned in advance.
D
Delamination
Separation of laminate layers, or of the skin from the core.
Instead of a crisp tap the hammer gives a hollow note. Large areas need structural repair; small ones can be injected with resin.
Dry reference area
An area on the same vessel known to be dry, measured for comparison.
Moisture figures only make sense against a reference on the same boat. A moisture number given without one cannot be read.
Dezincification
Loss of zinc from a brass alloy in seawater, leaving porous pink copper behind.
The fitting looks sound but can be broken by hand. Below the waterline, DZR brass or bronze should be used.
Damage survey
Establishing the extent and cause of damage after an incident.
Cause and effect matter: whether the damage came from the event or from a pre-existing defect decides the claim.
Draft
The deepest point of the vessel below the waterline.
Decides marina access, anchorages and haul-out planning.
F
Finding class A
Critical / safety, to be corrected before going to sea.
Flooding risk, fire risk and missing life-saving equipment fall here.
Finding class B
Short term, to be corrected this season.
Not dangerous today, but becomes class A if left.
Finding class C
Planned maintenance, an item now due.
Not a defect. Whether it becomes a negotiating point is the buyer's choice, not the surveyor's.
G
Gelcoat
The pigmented resin layer on the outside of the laminate. Protective, not structural.
The crack pattern names the cause: star cracks from impact, parallel cracks from flexing, crazing from age. The surveyor separates gelcoat cracks from laminate cracks by sounding and magnification.
Galvanic corrosion
Electrochemical wastage when dissimilar metals are connected in seawater and the less noble one dissolves.
Most often seen between propeller, shaft and drive leg. Anode consumption rate is the first indicator.
H
Handover protocol
The record signed at departure and arrival on a delivery.
Hull condition, engine hours, fuel level, inventory and photographs. The only objective record if anything is disputed later.
Hardstanding
The yard area where vessels are kept ashore.
Charged daily or monthly by length and not included in the survey fee.
I
Impeller
The rubber-vaned wheel in the raw water pump.
A wear item; a shed vane blocks the heat exchanger. A spare belongs aboard.
Insulation resistance
Measurement of whether circuits are leaking to the hull.
Low insulation in a marine environment is both a corrosion and a shock risk.
ISO 12217
The standard defining stability and buoyancy categories for boats.
The CE category (A/B/C/D) derives from it and states which sea conditions the vessel is designed for.
Insurance survey
Condition report required for a new policy or renewal.
Narrower in scope: safety equipment, hull integrity and fire risk come first.
K
Keel joint
Where the keel meets the hull, bolts and sealant.
A keel smile is not always structural, but hardened filler, a rusted bolt head and water in the bilge together are taken seriously.
L
Laminate
Glass fibre layers bonded with resin, the load-bearing structure of the hull.
Delamination sounds dull under the hammer. It is a structural defect and falls into class A.
Limitations section
The part of the report stating what could not be seen, and why.
As important as the findings: full lockers, fixed soles and the underwater area are recorded here when inaccessible.
Lodos
The south-westerly, usually bringing rain and swell.
The most common reason for waiting on Çanakkale and Marmara passages.
M
Moisture reading
Electrical measurement of moisture content in hull and deck laminate.
To mean anything the vessel must stand ashore and dry for at least a week. Thick antifouling, a wet surface and metal fittings all read falsely high. The report gives the difference from a dry reference area, not an absolute number.
Meltemi
The northerly seasonal wind that builds through the afternoon in the Aegean summer.
Long legs start early; five to six Beaufort is expected after midday.
N
O
Osmosis (blistering)
Blisters filled with acidic fluid, formed when water penetrates beneath the gelcoat of a GRP hull.
A single blister is not a defect; extent, depth and moisture readings decide. The report measures how saturated the laminate is, not how many blisters there are. Treatment means peeling, three to six months of drying and a barrier coat, a five-figure cost on a mid-size yacht.
P
Percussion testing
Tapping the surface rhythmically with a phenolic hammer and reading the change in sound.
Cheap and among the most informative methods. It takes experience: the same note is normal on thick laminate and a defect on thin.
Pitting
Localised deep corrosion craters in metal.
Average thickness can look healthy while one pit goes through the plate. A depth gauge and a visual map are used together.
Pre-purchase survey
Full-scope inspection before a buying decision.
Ashore and afloat together. Whatever could not be measured is recorded as a limitation.
Poyraz
The dry, cold north-easterly.
Builds a short steep sea quickly on Black Sea and North Aegean routes.
R
Rig tension
Measured tension in the standing rigging, using a gauge such as a Loos & Co.
Slack rigging lets the mast work; over-tight rigging compresses the deck. The target is typically fifteen to twenty per cent of breaking load, to the manufacturer's table.
Rigging life
The practical service life of stainless standing rigging, typically ten to twelve years in the Mediterranean.
Even with no visible defect, insurers may require renewal after this. On a 40-footer the cost runs into five figures.
Registration / tonnage certificate
The vessel's registration and tonnage documents.
Originals are required for sale, insurance and port formalities; copies are not accepted.
Refit
A comprehensive renewal of the vessel.
Without stage inspections, cost and quality drift; interim payments should follow progress.
S
Stray current corrosion
Direct current leaking from the vessel or the marina supply, eating metal fittings rapidly.
Far faster than galvanic action, a propeller can be lost in weeks. Measured with a zinc reference electrode and a clamp meter. The source is often the neighbouring boat.
Sacrificial anode
A zinc, aluminium or magnesium part deliberately allowed to dissolve to protect the hull.
Chosen by water type: zinc or aluminium in salt, magnesium in fresh. The wrong anode protects nothing. Half consumed by the end of a season is normal; an anode that has not wasted at all is not connected.
Shaft seal / stuffing box
The seal where the shaft passes through the hull.
A traditional gland drips a few drops a minute underway, that is correct. A dripless seal should not drip at all. A conventional gland that stays dry is over-tightened and wears the shaft.
Saildrive diaphragm
The rubber boot between hull and leg on a saildrive.
Manufacturers typically specify renewal at seven years. A cracked diaphragm is a flooding risk and a class A finding. Renewal requires a haul-out.
Seacock
The shut-off valve on every through-hull fitting.
A seized, non-operating or dezincified brass valve is a safety defect. Below the waterline double clamps are expected, and a softwood plug should be attached.
Sea trial
Testing the vessel running, under load.
Cold start, staged revolutions, ten minutes at maximum, steering and gear response, vibration and temperature logging. A survey ashore cannot produce these readings.
Scope agreement
Setting down in writing, before the work, what is included and what is not.
Most disputes come from a scope never discussed. Dismantling, coating removal and laboratory analysis are normally excluded.
Seaworthiness declaration
The skipper's written statement that the vessel is fit for the intended passage.
A condition of cover in most policies.
Survey preparation
Emptying lockers, providing access, having documents ready.
An unprepared vessel narrows the scope of the survey, and that appears in the report as a limitation.
T
Terminal
The end fitting of a wire, swaged, Sta-Lok or Norseman.
Cracks usually start at the mouth of a swaged terminal. Looked for with a 30× loupe and dye penetrant.
Thermal camera
An instrument that images temperature differences.
Shows bearings, electrical connections, exhaust leaks and slipping belts as faults while running.
True RMS clamp meter
Measures current without breaking the circuit and reads correctly on distorted waveforms.
Used for stray current tracing, charging circuits and inverter loads.
Transit log
The document issued for a foreign-flagged yacht navigating in Turkish waters.
Opened on entry and closed on departure. Crew list, port calls and duration are entered on it.
Travel lift
The hoist that lifts a vessel out of the water in slings.
Rated in tonnes; the booking and the fee belong to the marina. Wrongly placed slings damage the hull.
U
Ultrasonic thickness testing (UT)
Measuring plate thickness with sound, without removing the coating.
Compulsory on steel and aluminium hulls. Readings follow a grid plan, the pattern matters, not a single point. Ten per cent loss is monitored, twenty per cent is planned for, beyond twenty-five per cent plate renewal enters the conversation.
UT grid plan
Taking thickness readings at predetermined, repeatable points.
Random readings cannot be compared next year. A thickness report without a grid is a single snapshot.
V
Vibration meter
Measures vibration amplitude.
Propeller imbalance, a bent shaft and worn bearings show as vibration that rises with revolutions.
Valuation survey
Establishing market value.
Comparable sales, inventory and condition are weighed together; used for finance and probate.
W
Weather window
The period in which wind and sea suit the intended passage.
The schedule never overrides safety; waiting costs less than damage.
Z
Zinc reference electrode
An electrode lowered into the water to measure hull potential.
On a steel hull, protection between −0.80 and −1.05 V is accepted; below −1.10 V is over-protection and lifts the coating. Changing anodes without measuring is guesswork.