10 things to check before buying a used sailing yacht

The survey is too late to start asking questions

Most buyers commission a survey after they've already fallen in love with a boat. By that point, you're emotionally and sometimes financially committed — and the surveyor's bad news hits harder than it should.

The smarter approach is to do your own pre-viewing intelligence work first. That's exactly what BoatQuest Intelligence Reports are built to do — but whether you use AI or go it alone, here are the ten things every buyer should investigate before spending a day travelling to a viewing.

1. Keel attachment — the single most important check

A suspect keel is the most expensive problem a sailing yacht can have. On GRP boats, look for:

• Rust staining around the keel/hull join — iron keels weep rust through sealant as bolts corrode
• Cracks or crazing in the gelcoat at the keel root — these can indicate movement
• Daylight gaps between keel and hull when viewed from underwater (if antifouled, this is hard to spot without lifting)

Known problem boats: Bavaria yachts from 2005–2012, Jeanneau Sun Odyssey models from the same era, and Dehler 34s all have documented keel bolt issues in owner forums. Always ask when keel bolts were last inspected.

2. Osmosis — serious or cosmetic?

Osmotic blistering (osmosis) affects polyester GRP hulls when water penetrates the outer gelcoat layer. The vast majority of cases are cosmetic — surface blisters that cost a few thousand pounds to treat. But severe osmosis reaching the structural laminate is a different matter.

What to look for before the survey:

• Small circular blisters on the bottom paint, especially when the boat is newly lifted
• A vinegary smell inside blisters if you can get close enough to pop one (indicates active osmosis)
• Previous epoxy barrier coats — a sign the problem has been treated before

Ask the seller directly: has this boat ever been treated for osmosis? If yes, get paperwork. Any reputable yard will have records.

3. Rig condition — hours in the rig matter more than age

Standing rigging (shrouds and stays) has a service life. Most surveyors recommend replacing wire rigging every 10 years or 20,000 miles, whichever comes first. Rod rigging lasts longer but is harder to inspect.

Check:

• When was the standing rigging last replaced? Get dates.
• Look at swaged terminals (where wire enters the fitting) for cracking or corrosion — this is where rigging fails
• Check the mast base and partners (where the mast enters the deck) for corrosion or movement
• Running rigging condition is less critical but tells you how the boat has been maintained overall

4. Engine hours vs service history — one without the other means nothing

An engine with 500 hours and no service records is riskier than one with 2,000 hours and a full history. What you actually need is both.

The questions to ask:

• When were impeller, belts, and anodes last replaced?
• Has the heat exchanger ever been serviced?
• Are there any current issues — overheating, smoke, excessive vibration?
• For inboards: when was the cutless bearing last replaced?

A good test: start the engine cold at the viewing (not pre-warmed by the seller) and watch for blue smoke on startup, which indicates worn piston rings or valve seals.

5. Electrics — the iceberg issue

Electrical problems are the most common cause of post-purchase regret. They're invisible until something stops working, and rewiring a boat is extraordinarily expensive.

Look for:

• Wiring that looks like spaghetti — previous owner DIY additions are a red flag
• Corrosion on terminals and connections
• A battery bank that's original — batteries over 4–5 years old are likely to need replacing (£300–800)
• Check that all instruments, nav lights, and pumps work before the viewing ends

6. Deck hardware and sealants — small leaks become big problems

Water ingress through deck fittings is one of the most common causes of structural delamination in GRP boats. Chainplates, stanchion bases, and mast bases are the usual culprits.

How to spot it:

• Look for tide marks and staining on the headliner below deck hardware
• Press on the deck around fittings — any softness indicates wet coring (a serious and expensive repair)
• Look underneath hatches and portlights for rust staining or mould

7. Sails — check age and UV condition

A complete suit of cruising sails costs £5,000–15,000 to replace. If the sails are original on a 15-year-old boat, budget for new ones.

What to check:

• UV cover condition on furling headsails (the coloured strip along the leech) — cracking means the main sail cloth is also degraded
• Stitching along seams — rotten thread lets go suddenly under load
• Ask how many offshore miles the sails have. Coastal miles are gentle; offshore miles are hard

8. Chainplates — hidden, critical, expensive

Chainplates are the metal fittings that attach the standing rigging to the hull. They're often hidden behind interior liners and can corrode undetected for years. Chainplate failure means losing the rig.

This is almost always a surveyor job — but you can ask the seller when they were last inspected and whether there's any record of it.

9. Documentation — check before you fall in love

Before you visit a boat, ask for:

• Part 1 registration or Small Ships Register certificate (confirms the boat exists legally)
• VAT paid status — buying an EU-built boat that has re-entered UK waters without VAT documentation creates a significant liability
• RCD (Recreational Craft Directive) compliance — required for boats built after 1998 sold in the UK
• Any outstanding finance — the boat can be repossessed after sale if finance is attached. HPI check costs £30 and is non-negotiable.

10. Price position — are you overpaying?

The asking price is not the market price. Boats sit on the market for months, sometimes years. A boat that's been listed for 300 days at the same price has an owner who either can't sell or doesn't need to — and both mean you have negotiating power.

This is where BoatQuest Intelligence Reports are particularly useful: we benchmark every listing against comparable boats on the market right now, give you a percentile position, and estimate realistic negotiation headroom.

The bottom line

None of these checks replace a professional marine survey from a qualified RICS or IIMS accredited surveyor. But doing this work before the survey means:

1. You only commission surveys on boats that deserve it

2. You arrive at the viewing with informed questions

3. You negotiate from knowledge, not enthusiasm

Generate a free BoatQuest Intelligence Report on any listing before you book that train ticket.