A pre-purchase survey is the cheapest insurance a yacht buyer will ever buy. It typically runs USD 20 to USD 25 per foot for a thorough job, USD 12 to USD 15 for a cursory one, and the difference between the two outcomes can be six figures.
This is the checklist our team hands to buyers before survey day, with the items surveyors routinely skip noted at the bottom.
The dry inspection: hull, keel, rudder
The boat should be hauled and dried for at least twenty four hours before the surveyor arrives. Moisture readings on a wet hull are unreliable. Buyers who agree to a same day haul and survey are saving the seller money at their own expense.
On the hard, the surveyor walks the hull with a percussion hammer and a moisture meter. Soft spots, blistering, gelcoat crazing, prior repairs that did not bond properly, keel attachment hardware on sail vessels, rudder bearing play, propeller shaft alignment, cutless bearing wear, strut alignment.
Through hulls get individual inspection. Each seacock should open and close fully. Bronze fittings should not show pinkish dezincification. Hose clamps should be doubled where required and corrosion free. A boat with twelve through hulls is twelve potential sinkings on a long passage.
Below the waterline: blistering, gelcoat, anodes
Osmotic blistering is a fibreglass hull condition where moisture penetrates the gelcoat and creates fluid filled pockets. Small isolated blisters are common on boats over fifteen years old. Wide field blistering across the hull is a much larger problem, and a peel and re-laminate job runs USD 1,500 to USD 2,500 per foot.
Anode wear tells the truth about electrolysis history. Anodes that are seventy percent consumed in a year are normal. Anodes consumed in three months mean stray current somewhere in the marina or onboard, and the next set of anodes will not save the running gear.
Mechanical: engine hours, oil analysis, alignment
Engine hours are a useful proxy for use, not a measure of condition. A 2,000 hour diesel with documented maintenance is in better shape than a 600 hour diesel that sat idle for three winters. The maintenance log matters more than the hour meter.
Oil analysis on each engine and the generator is non-negotiable. The lab report shows wear metals, coolant intrusion, fuel dilution, and combustion byproducts. A buyer who skips oil analysis is skipping the only test that sees inside the block without opening it.
Engine alignment is checked under load on the sea trial. Vibration at cruise RPM is the most common symptom of misalignment, worn mounts, or a bent shaft. Each of those is a fix in the USD 4,000 to USD 12,000 range.
Electrical and systems
The electrical survey covers shore power inlets, the main panel, GFCI and ELCI protection, galvanic isolators, the inverter and charger, alternator output, and battery state of health. Lithium retrofits are increasingly common and add a layer of complexity that older surveyors sometimes miss. The buyer should confirm the surveyor is current on lithium banks if the vessel has one.
Systems beyond power: watermaker production rate and salinity, refrigeration cooling capacity under load, air conditioning seawater pump flow, HVAC plenum cleanliness, head and holding tank function, bilge pumps tested wet, fire suppression in the engine room within service date, EPIRB registration current.
Sea trial: what to watch under load
Sea trial is the moment the boat tells you what the slip would not. Departure manoeuvres in close quarters, throttle response at idle, low RPM cruise, mid-range cruise, full throttle for at least three minutes, deceleration, reverse, return to slip.
Watch for vibration spikes, exhaust colour transitions, water in the exhaust stream, gauges holding, autopilot tracking, gyro stabilizer engagement and disengagement, generator parallel load. Engine room temperatures should be logged at the start and end of the trial. A ten degree rise across an hour is fine. A thirty degree rise is the cooling system telling you something.
The paperwork survey
The paperwork survey is the survey buyers skip and regret. Title chain back five owners, lien search through USCG and state, insurance loss history report, prior accident filings, sales tax payment history, builder's certificate or original USCG documentation, current state registration if applicable.
A boat with a paperwork gap is not unsellable. It is unsellable at full price. The seller's broker will know. The buyer who runs the paperwork survey before the offer has a negotiating lever the seller did not see coming.
What surveyors rarely flag
Things our team has watched buyers discover after closing that should have been caught at survey: tankage cross contamination from a prior diesel spill into water tanks, holding tank cracks that show only when half full, dripless shaft seals at end of service life, soft balsa coring under deck hardware that did not show on the survey because the hardware was not removed, owner installed wiring that bypasses the breaker panel, prior insurance claim repairs that were never finished, and missing or outdated lithium BMS firmware.
None of these require a separate trade. They require a surveyor who is willing to spend the extra two hours, and a buyer who is willing to pay for it. We consider a survey under four hours on any vessel over fifty feet to be a flag in itself.
The buyers who close on the right boat at the right price are not the ones who hurry. They are the ones who pay for the long survey, run it dry then wet then paperwork, and read the report carefully before they sign anything else.