Used Boat Inspection Checklist (UK) Before You Buy

Work through it in the order below. Take a photo of everything you note, including the things that look fine — a dated picture of a sound keel joint is worth as much later as a picture of a crack. If the seller hurries you past any section, that is a finding too.

1. Before you go: the paperwork

• Proof of ownership. Ask for the original bill of sale from when the seller bought the boat, and ideally the chain of earlier ones. Registration (Part 1 or the Small Ships Register) is not proof of ownership in the UK; it is a record of who registered it.
• VAT status. Ask for the original invoice or other evidence that VAT was paid. A boat without it can be hard to sell on and may attract questions when it moves between countries.
• Hull identification number. Get the HIN (also called a CIN) from the seller in advance and check it against the builder's plate and the transom when you arrive. Our hull number guide and decoder explains what the characters mean.
• Builder's documents. For boats sold new in the UK or EU from 1998 onwards: the declaration of conformity and the owner's manual. Older boats will not have them, which is normal.
• Service and survey history. Engine service receipts, the last survey, yard invoices. Gaps are not fatal, but they set the questions for the viewing.
• Outstanding finance. There is no central register for boats. Ask directly, and get the answer in writing in the sale agreement.

2. The hull, out of the water if at all possible

• Blisters. Small raised bumps in the gelcoat below the waterline can be osmosis. A few are common on older GRP boats; a widespread rash is a negotiation or a walk-away. Note the size and the count.
• Crazing and repairs. Spider-web cracks around fittings and corners; patches of slightly different colour or texture that show an earlier repair. Ask what happened.
• The keel joint. On a bolted fin keel look for a gap or a rust line along the hull-to-keel joint (the "smile"), and inside for rust around the keel bolts and cracked bedding. Grounding damage shows here first.
• Rudder and skeg. Push the rudder sideways: play in the bearings is felt as a knock. Look for water weeping from the rudder blade — a sign the foam core is wet.
• Through-hull fittings and seacocks. Each one should turn freely by hand. Bronze or composite is good; plain brass fittings corrode and are a known failure point. Count them and note any that are seized.
• Anodes. Half-eaten is working; untouched after a season suggests a wiring fault; missing is a question.
• Antifouling. Many thick layers flaking off add work; a bare patch tells you nothing bad on its own.

3. The deck and the rig

• Soft spots. Walk every part of the deck in soft shoes and press around the mast base, chainplates, stanchions and winches. Any sponginess means water in the core. This is the single most expensive deck problem to fix.
• Fittings. Are the stanchions, cleats and winches backed with plates below deck? Look from inside for rust streaks and damp around their bolts.
• Hatches and windows. Open and close every one. Look for staining on the headlining below them.
• Standing rigging. Ask when the wire was last replaced. Many insurers ask for replacement roughly every ten years; broken strands at the terminals or rust weeping from swages are a replace-now finding, not a monitor.
• Running rigging and sails. Chafe, stiffness and sun damage. Look at the sails' stitching along the leech and at the UV strip on a furling headsail.
• Mast and boom. Corrosion where stainless fittings meet aluminium, cracks at the spreader roots, and whether the mast step and partners are sound.

4. Inside

• The bilge. Dry and clean is good; oily is an engine question; salt crust is a leak question. Lift every board you can.
• Stringers and bulkhead tabbing. Where the bulkheads meet the hull, the fibreglass tape should be intact, not cracked or lifting. Lifted tabbing can follow a grounding.
• Chainplates. From inside, look for rust and for staining where the rigging loads come through the deck.
• Smell. Diesel, damp, gas and sewage each say something. A boat aired out for the viewing will not hide a long-standing damp problem in the lockers.

5. The engine

• Cold start. Ask that the engine is not run before you arrive. Watch the exhaust at start-up: blue smoke that clears is wear; black is fuelling; white that persists is water or head trouble. Listen for a knock.
• Hours and history. Hour meter against the service receipts. No receipts and a suspiciously clean engine bay is a question, not an answer.
• Mounts, belts, hoses. Cracked or collapsed mounts, glazed belts, hardened or bulging hoses, worm-drive clips rusted through.
• Raw-water side. The impeller's age, the condition of the heat exchanger and the exhaust elbow (a common and expensive failure on older diesels).
• Drive. On a shaft drive, grab the shaft and feel for play in the cutless bearing; look at the stern gland. On a saildrive, ask for the date of the last diaphragm change and look at the drive's anode.
• Under way. If you can, run it to temperature, engage ahead and astern, and hold cruising revs for ten minutes while watching the temperature and looking for drips.

6. Electrics, gas and safety gear

• Batteries. Date stamps, terminal corrosion, whether they are strapped down, and whether the charging system shows a sensible voltage with the engine running.
• Wiring. Tidy, labelled and fused is a good sign. Household cable, twisted joints and chocolate-block connectors in the bilge are not.
• Gas. The bottle locker should drain overboard; the hose should be in date and the regulator not corroded. A recent gas safety certificate is a plus; its absence is a cost to budget.
• Safety equipment. Flares, liferaft service, fire extinguishers and the EPIRB all carry dates. Expired kit is a cost line, not a reason to walk, unless the seller has described the boat as "ready to go".

7. After the viewing

Write your findings up the same day while they are fresh, with the photos next to each one. Then decide three things: whether to make an offer, what to make it conditional on, and whether to commission a marine survey. For most purchases of any size the answer to the last one is yes — your inspection is what makes the survey money well spent, because you already know where to point the surveyor.

If the boat is listed on a marketplace that uses SoundHull, the seller's verified history gives you the hull number check, the earlier paperwork and a signed inspection before you travel. It does not replace this checklist or a survey; it tells you whether the trip is worth making.

Questions people ask

Do I need a survey if I have done this checklist?

Usually yes. The checklist tells you whether the boat is worth a survey and where to point the surveyor; a surveyor brings moisture meters, hammer-sounding of the hull and experience of the boat type. For an older or larger boat, insurers will often ask for a survey anyway.

Can I check whether there is finance on a used boat?

Not from a public register — the UK has none for boats. Ask the seller directly, state in the written sale agreement that the boat is sold free of any charge or finance, and keep the signed agreement.

What is the most expensive thing to miss?

Water in the deck core or a wet, delaminated hull. Both are hidden, both are slow to fix and both are found by pressing, tapping and looking for staining rather than by looking at photos.

Does registration prove the seller owns the boat?

No. Part 1 registration and the Small Ships Register record who registered the vessel; ownership is shown by the bill of sale and the chain of earlier ones.