Every term in your report: what it is, which measurement produced it, and what it means for you.
This page explains the terms that appear in survey reports and delivery contracts, in the sense they carry in the field. The aim is not vocabulary for its own sake: when a term stops you while reading your report, you should be able to see which measurement it comes from and what it means for you.
How to use it: press Ctrl+F (or "find on page" on a phone) and type the term. Entries are alphabetical. If a term in your report is missing here, write in, we will add it.
The urgency class given to every finding. A: affects safety, to be rectified before the boat goes to sea. B: within this season. C: planned maintenance. The class describes urgency, not cost.On site: The report summary opens with the A-grade findings.Related page: Reading a survey report
A zinc, aluminium or magnesium block that corrodes in place of the metals it protects. Zinc in salt water, aluminium in salt and brackish, magnesium in fresh. The wrong alloy gives no protection at all.On site: An anode more than half wasted is reported with a recommendation to replace.Related page: Cathodic protection survey
Measures combustion gas escaping past the rings into the crankcase. High blowby points to ring or bore wear. Read together with a compression test, never alone.On site: Done with an independent engine technician, with the engine at working temperature.Related page: Engine survey
A camera on a flexible probe for spaces that cannot be opened: cylinders, tanks, under the bilge, inside a mast. It is the most practical way to see what cannot otherwise be seen without dismantling.On site: Leak marks behind linings are often first seen through the borescope.Related page: Survey equipment
Carvel: planks laid edge to edge, smooth surface. Clinker: planks overlap. Carvel is checked at the caulking seams, clinker at the rivet line. In both, fastening corrosion is what decides the boat's future.On site: On site, the first thing we look at is rust staining around the fastenings.Related page: Wooden yacht survey
The system that keeps a metal hull and its fittings from corroding: anodes, the bonding circuit and, where fitted, impressed current. Verified by measuring hull potential against a zinc reference electrode.On site: Measured with the reference electrode afloat, with shore power on and off.Related page: Cathodic protection survey
Filling the seams between planks on a wooden hull with cotton and compound. An opening seam usually means drying and movement rather than leakage; the survey looks behind the seam, at the fastening.On site: Dried, shrunk caulking shows as a fine opening line along the seam.Related page: Wooden yacht survey
The metal fitting that carries rig load into the hull. When the deck bedding ages, water enters and leaves salt traces and corrosion around it. One of the most common hidden defects on both GRP and wooden boats.On site: Rust staining where it passes through the deck is the first sign of hidden corrosion.Related page: Rig survey
Measuring sealing pressure in each cylinder. The spread between cylinders says more about an engine's condition than any single absolute figure.On site: A separate service coordinated with an independent engine technician.Related page: Engine survey
Separation between composite layers. Sounded with a phenolic hammer, sound laminate rings; delaminated laminate answers hollow, like a drum. A thermal camera shows it as a different heat pattern.On site: A dull note under the sounding hammer is read together with the moisture meter.Related page: GRP survey
How deep the hull sits below the waterline. It decides marina entry, anchorage choice and lifting arrangements, and is taken into account when planning a delivery route.On site: For marina and travel lift planning, the measured draft counts, not the brochure figure.Related page: Marina guide
The height between the waterline and the deck. Relevant to loading, stability and how much water the deck takes.On site: On an overloaded boat the waterline mark shows freeboard lower than it should be.Related page: GRP survey
Electrochemical wear that occurs when dissimilar metals are in contact in seawater. Anodes take this on themselves and so protect propeller, shaft and bearings.On site: White powdering or green oxide shows where dissimilar metals meet.Related page: Cathodic protection survey
The outer protective layer of the laminate. Spider cracking is usually cosmetic; star cracks indicate impact; a crack running along a straight line indicates structural movement.On site: Hairline cracks are seen under the loupe and read together with moisture readings.Related page: GRP survey
Glass-reinforced polyester or vinylester composite. Most of the Turkish second-hand fleet is built this way. The main survey items are moisture, delamination, gelcoat cracking and osmosis.On site: Most boats on the Turkish second-hand market are GRP.Related page: GRP survey
Where raw water takes heat from the engine's coolant. Blockage and salting are the most common causes of overheating; broken impeller vanes usually collect here.On site: On sea trial the in-out temperature difference is read with an infrared thermometer.Related page: Engine survey
Measuring how well electrical circuits are insulated. Resistance falls in cables that have taken moisture; this is often the source of stray current and galvanic problems.On site: A low value points to damp or deteriorated cable.Related page: Electrical survey
The bolts that hold the keel to the hull, and the laminate around them. The most-checked area after a grounding: cracks, rust weeping or seepage in the bilge.On site: Rust and water around the bolts inside are read together with any crack at the joint outside.Related page: GRP survey
The path from the mast to the hull and to the ground plate in the water. Continuity is measured; a broken bond is a risk both in a strike and in everyday galvanic protection.On site: Continuity and corrosion of the bonding conductors are checked.Related page: Electrical survey
Reads moisture in the laminate without penetrating the surface. For the reading to mean anything the boat must have been ashore and dry for at least a week; on a hull just lifted out, values read misleadingly high.On site: For reliable readings the boat must have been ashore and dry for at least one week.Related page: Survey equipment
Water passing through the gelcoat and forming acid inside the laminate, raising blisters that smell of vinegar. High moisture alone is not osmosis; blistering, smell and drying behaviour are read together.On site: The first sign is lentil-sized blisters under the antifouling.Related page: Osmosis survey
A hard plastic-tipped hammer that finds voids and delamination by sound without marking the hull. Used to confirm what the moisture meter indicates.On site: The hull is tapped on a grid and dull areas are marked on the sketch.Related page: Survey equipment
The seal where the shaft leaves the hull. On a traditional stuffing box, a slow drip under way is normal and a drip at rest is not. Dripless types should not weep at all.On site: The drip rate under way and salt build-up around the gland are recorded.Related page: Engine survey
The conformity framework for boats placed on the EU market; covers design category (A-D) and the builder's declaration. The document chain matters for a boat moving from Turkey into the EU.On site: The CIN and builder's plate are checked against the declaration of conformity.Related page: Regulations
Everything that holds the mast up: mast, boom, spreaders, standing rigging and its terminals. Ten to twelve years is the commonly accepted renewal interval for wire rigging, but the terminals and the wire decide, not the calendar.On site: Terminals are checked under a 30× loupe and tension with a rig tension gauge.Related page: Rig survey
The stage where the boat is tested under load. Cold start, staged increase in revolutions, temperature behaviour, vibration, steering and sail handling are measured here. Most defects invisible ashore show up at this stage.On site: It starts from cold; temperatures and vibration are measured at each rpm step.Related page: Sea trial
The shaft running true with the engine and its bearing. Misalignment produces vibration, bearing wear and seal leakage; it shows on sea trial as vibration that rises with revolutions.On site: The vibration meter points to misalignment across the rpm steps.Related page: Engine survey
The standard describing a boat's behaviour against capsize. A survey does not calculate stability; it records weight distribution, loading and any modifications made.On site: Heavy equipment added later can affect the boat's design category.Related page: Regulations
An independent, measurement-based record of a boat's condition. Pre-purchase, insurance, valuation, damage and condition surveys are separate scopes. A survey is not a guarantee; it is the record of a condition on a given date.On site: A pre-purchase survey is the sum of the inspection ashore and afloat.Related page: Survey types
Shows temperature differences at the surface. Used to find areas holding moisture, warming terminals in an electrical panel and abnormal hot spots on an engine.On site: The switchboard is scanned under load; hot spots are reported with a photo.Related page: Survey equipment
The document issued for a foreign-flagged vessel cruising in Turkish waters. Opened at the port of entry and closed on exit; crew list and route changes are recorded on it.On site: On a foreign-flagged boat its validity is checked before a delivery.Related page: Transit log guide
A meter that reads current accurately when the waveform is not a clean sine. Used for stray current, charging systems and consumption; an ordinary meter misreads these.On site: Charging and leakage current are measured without breaking the cable.Related page: Electrical survey
Measuring plate thickness in steel and aluminium hulls with sound. Readings taken on a grid are compared with original scantlings to calculate wastage.On site: On steel boats the thinnest points are usually in the bilge and at the waterline.Related page: Steel and aluminium
The lowest volume in the boat. Standing water, oil traces, salt crystals and smell make the bilge the most readable record of how the systems have been treated.On site: The colour and taste of bilge water (salt, fresh, oily) point to its source.Related page: GRP survey
Electrically connecting all metal fittings so they sit at the same potential, bringing galvanic corrosion under control. Continuity is verified by measurement.On site: A broken bond leaves that metal outside the cathodic protection.Related page: Cathodic protection survey
Combustion gas escaping past the piston rings into the crankcase. Pressure and smoke at the oil filler show the state of bore and ring wear.On site: Heavy vapour from the crankcase breather is the first clue on site.Related page: Engine survey
The light material between skins in a sandwich laminate (balsa, foam). Wet, it loses its structural contribution, usually the real target of moisture readings.On site: Wet core shows as a distinct high area on the moisture map.Related page: GRP survey
The chemical hardening of resin. Without the right temperature and humidity the cure does not complete, and an under-cured laminate never reaches its designed strength.On site: Under-cured laminate may feel hard but has not reached full strength.Related page: New-build supervision
FairingTR: Macunlama (fairing)
Filling and sanding a surface back to its intended shape. Excessive fairing compound can hide a repair rather than complete it.On site: Fairing filler over a repair can hide the original damage; moisture and sounding are checked beneath it.Related page: GRP survey
The document setting out which ply goes down in which order and orientation on a composite hull. It is the technical backbone of a build contract.On site: Repairs are checked against the original schedule by thickness and ply count.Related page: New-build supervision
The route a force takes through the structure. Whether a crack is cosmetic or structural is decided by whether the load path runs through it.On site: Load from deck hardware is traced through to the backing structure.Related page: New-build supervision
The list of shortfalls found before handover. Numbered and photographed, it becomes the basis for withholding the balance payment.On site: On a pre-delivery survey, each snag is listed with a photo and its location.Related page: New-build supervision
Tapping a laminate with a phenolic hammer and reading the change in sound to find voids and delamination. It is the second piece of evidence that confirms a moisture reading.On site: Hull, deck and coachroof are sounded on a grid.Related page: GRP survey
Accelerated wastage of metal caused by leaking current aboard. Unlike galvanic corrosion, it has an external source.On site: Anodes wasting within weeks is the typical sign of stray current.Related page: Cathodic protection survey
The fore-and-aft attitude of the boat. Shift the weight distribution and draft, fuel consumption and handling all change with it.On site: The boat's attitude is observed at each speed step on sea trial.Related page: Sea trial
A welding procedure specification: which method, with which parameters and by which qualified welder, on a metal build.On site: In build supervision, welder qualification and the WPS are checked together.Related page: New-build supervision
Report Language: Phrases You Will Meet
Phrase in the report
What it means in practice
"Moisture elevated relative to the reference area"
There is a difference against an area accepted as dry. Not a defect on its own; read with sounding and drying behaviour.
"Hollow response on sounding"
Layers may be separating. The extent is marked and its dimensions recorded.
"Limited to visual inspection"
That area could not be reached without dismantling. The limitation is written into the report; it does not mean there is no problem.
"Shaft seal weeping under way"
Normal on a traditional stuffing box. Weeping at rest indicates adjustment or wear.
"Anodes below 50%"
They may not last until the next lift-out. Given as class B or C.
"Crack indication at terminal"
Fatigue beginning at a rig fitting. A class A finding: rectify before going to sea.
"No record found"
There is no documentation that the work was done. It does not mean it was not done, it means it cannot be verified.
Units
Unit
Measures
Note
NM (nautical mile)
Distance
1 NM = 1,852 m. Delivery distances are given in NM.
Knot
Speed
1 knot = 1 NM per hour.
ft / m
Length overall
1 ft = 0.3048 m. Survey fees are usually quoted per foot.
GT (gross tonnage)
Volume
A measure of volume, not weight; master's licence classes are defined in GT.
mm
Plate thickness
Ultrasonic readings are reported in millimetres.
mV
Hull potential
Read against a zinc reference electrode in cathodic protection measurement.
Bar / psi
Compression
The spread between cylinders matters more than the absolute figure.
Frequently Asked Questions
Write in. We will explain it to you and add it to the glossary. A report being readable is part of the report.
Moisture alone does not decide. The conditions of the reading (how long the boat had been ashore), the sounding result and the drying behaviour are weighed together, and the report states all three.
Class A findings concern safety and should be rectified before anything else. Negotiation usually happens around class B items.
No. A survey records what was found, on a given date, within a stated scope. Areas that could not be reached are written into the report as limitations.
Yes. The Turkish version of this page carries the same terms, and reports are prepared in English or Turkish as you prefer.
