A pre-purchase yacht survey is an inspection of a used boat by an independent marine surveyor, paid for by the buyer, before the sale goes through. The surveyor checks the hull, deck, rig, machinery, systems and safety gear, runs the boat on a sea trial, and writes a report that grades each finding by urgency. You use it to decide whether to buy, to renegotiate the price, and to get insurance and finance.
The survey happens after your offer is accepted and before the deal closes. This guide walks through the order of events, what the surveyor will and won't do, how to choose one, and how to turn the report into money off the price.
Where the survey fits in the purchase
- Offer, subject to survey and sea trial. Your offer, written on the broker's form or a standard one such as the YBAA, MYBA or RYA agreement, names a deadline for the survey and for your written acceptance or rejection.
- Deposit. Usually 10 percent, held by the broker or in escrow.
- Book the surveyor and the haul-out. You pay the surveyor, the yard and any engine specialist, whether or not you buy.
- Survey day. Inspection afloat and ashore, haul-out, sea trial.
- Report. Within a few working days. Read the priority items first.
- Decide in writing. Accept, renegotiate, or reject, before the contract's deadline.
- Close. Final payment, bill of sale, registration and insurance in your name.
Miss the written-notice deadline and many agreements treat the survey as accepted. Put the date in your calendar the day you sign.
What the surveyor inspects
Scope varies between surveyors, so ask for it in writing before you book. A typical pre-purchase survey on a 10 to 20 metre yacht covers:
| Area | What gets checked |
|---|---|
| Hull below the waterline | Osmotic blisters, cracks, repairs, keel and keel bolts, rudder and bearings, shaft, P-bracket, propeller, through-hulls and seacocks, anodes |
| Hull and deck structure | Moisture readings and percussion sounding for wet core and delamination, stress cracks, hull-to-deck joint, stanchion and fitting bases |
| Rig and sails (sail) | Mast, boom, standing and running rigging, chainplates, furlers, winches. A full rig survey at height is a separate job |
| Engine and drive | External condition, leaks, mounts, exhaust, cooling, belts, hours, cold start, behaviour under load on the sea trial |
| Fuel and gas | Tanks, hoses, venting, shut-offs, LPG locker and drain, gas detector |
| Electrical | Batteries and their securing, charging, wiring standard, overcurrent protection, shore power, galvanic isolation |
| Plumbing | Water, holding tanks, bilge pumps and float switches, heads |
| Steering and controls | Cables or hydraulics, emergency tiller, throttle and gear |
| Safety equipment | Life raft and service date, fire extinguishers and fixed system, flares, lifejackets, CO and smoke alarms, navigation lights |
| Paperwork | HIN, builder's plate, registration, CE category or capacity plate, service records |
US surveyors usually measure what they find against the ABYC standards, NFPA 302 for fuel and electrical systems, and the US Coast Guard rules in 33 CFR. In the UK and Europe the references are the Recreational Craft Directive (CE marking), ISO standards and, for gas, the Boat Safety Scheme where it applies. For the full system-by-system list, see our yacht survey checklist.
What it doesn't cover
A survey is non-invasive. The surveyor won't cut out a sample of the deck, lift fixed floors, strip the joinery, drain the tanks or open the engine. Areas that can't be reached are listed as not inspected, and that list matters: a page of exclusions on an older boat tells you where the risk sits.
Two things are worth adding on most boats:
- An engine survey by a diesel specialist or the manufacturer's dealer (a Volvo Penta, Yanmar or Caterpillar technician, for example), with compression or blow-by checks and a full load test.
- Oil analysis. A sample from the engine, gearbox and generator, sent to a lab such as Blackstone Laboratories in the US. Raised metals, coolant or fuel in the oil show wear the sea trial can't. The results take about a week, so take the samples on survey day.
The haul-out and the sea trial
The haul-out puts the boat on the hard for a few hours so the surveyor can see and sound the underwater hull. Book a short-haul slot with the yard yourself and ask the surveyor how long they need. Ask the yard to lift early: a hull that has dried for an hour or two gives more reliable moisture readings.
The sea trial runs one to two hours. The surveyor watches the engine reach full revs and its temperatures and pressures under load, checks steering, vibration and the shaft seal, and on a sailing yacht looks at the rig under sail if the weather allows. On motor yachts the sea trial is where the engine surveyor earns their fee.
Engines are often inspected cold first, then run on the sea trial. A seller who has already warmed the engine before you arrive has removed the best chance to hear a hard start.
How to choose a surveyor
There's no licence for yacht surveyors in the US or the UK. Accreditation by a professional body is the usual test:
| Body | Where | Designation to look for |
|---|---|---|
| SAMS (Society of Accredited Marine Surveyors) | US, international | AMS, with a yachts and small craft endorsement |
| NAMS (National Association of Marine Surveyors) | US, international | NAMS-CMS |
| IIMS (International Institute of Marine Surveying) | UK, international | Full member or Certified Marine Surveyor |
| YDSA (Yacht Designers and Surveyors Association) | UK, Europe | Full member |
Australia differs for commercial vessels: their surveyors must be accredited by AMSA.
Before you book, ask:
- How many boats of this type and builder have you surveyed in the last year?
- Will you check the boat against current ABYC standards (US) or the RCD and ISO standards (Europe)?
- What's included, what's extra, and can I see a sample report?
- Do you carry professional indemnity insurance?
- Which insurers and lenders accept your reports?
Check the last point with your insurer before you book. Some marine insurers, Markel and BoatUS among them in the US and Pantaenius in Europe, ask for a recent survey on older or higher-value boats and may name the accreditations they accept. One survey can then serve the purchase and the insurance. Our guide to the boat insurance survey covers what insurers look for.
For prices, see how much a boat survey costs. In short: in the US, expect $25 to $35 per foot for the survey, with the haul-out, engine survey and travel on top.
How to read the report
Most reports open with a summary and a list of recommendations graded by priority. The wording differs between surveyors, but the grades usually split into:
- Safety or immediate: fix before the boat is used. A seized seacock, an expired life raft, a gas leak.
- Before insurance or within a set period: an insurer will usually require these done.
- Maintenance and advisory: worn items and things to watch.
Read the priority items first, then the list of areas not inspected. Our article on the marine survey report explains each section and how a good finding is written.
The report also usually gives a market value. Surveyors base it on comparable boats sold or for sale, from sources such as YachtWorld listings and price guides like BUC or J.D. Power, adjusted for the condition found. A lender will lend against this figure, so a value well below the agreed price affects your finance as well as your negotiation.
Using the report to renegotiate
- Price the findings. Get a written yard quote for every safety and insurance item. A seller argues with an estimate far more than with a quote on the yard's letterhead.
- Separate what was known from what's new. An old boat with tired upholstery was priced that way. Wet deck core, a failing gearbox or crevice corrosion in a chainplate wasn't.
- Choose the ask. A price reduction, the seller fixing the items before closing, or a holdback in escrow until the work is done. A price reduction is the simplest: the seller's yard won't be choosing the quality of the repair.
- Send it in writing, before the deadline, through the broker, with the report pages and quotes attached.
If the findings are structural, such as a soft hull, keel grounding damage or widespread osmosis on a boat sold as dry, walking away is often cheaper than any discount. That is what the contingency is for.
For surveyors: the report is where the day goes
The client sees one day on board. The surveyor then spends another day or two at the desk turning notes, voice memos and a few hundred photos into a report the buyer, the insurer and the lender can act on.
We built Axsail for that second part. You talk through the boat as you inspect it and take photos as you go. Axsail writes each observation up as a finding with its system, location, reading and recommendation, puts the photos on the findings they show, and asks for a missing reading while you're still at the battery bank. The draft report, with particulars, grades and a valuation section, is ready minutes after the walk-round. You review it and sign. To try it on your next pre-purchase survey, start free.