What a yacht's maintenance record tells you that the vessel cannot

What an inspection can see. Where it stops

A competent physical inspection establishes a great deal. Corrosion, wastage, leaks, distortion, wear at the points where wear shows, the state of coatings, the condition of couplings and mounts, the behaviour of a system when it is run. None of that is in doubt.

What it cannot establish is history. Nobody opens a main engine during a pre-purchase survey. The examination is external, functional and documentary. The internal condition of a machine is inferred rather than observed. Inference needs evidence. The evidence is the record.

The gap this leaves is not a small one. The most expensive machinery aboard a yacht is precisely the machinery whose internal condition cannot be seen. It is also the machinery whose deterioration from neglect is slowest to become visible.

What a maintenance record is at this size

On a larger yacht the record is not a folder of invoices. It is a planned maintenance system: a schedule holding every maintenance task for every item of equipment aboard, each task tied to an interval expressed in running hours or in elapsed time, each with a record of when it was last completed and by whom.

Its value to a buyer is structural. It sets out the work that was required and the work that was done, in the same place, in a form that can be compared. Everything else in this article follows from that comparison.

Why a missed interval is not a deferred cosmetic

Owners and brokers reasonably describe outstanding maintenance as a job for the new owner. On paint and upholstery that is fair. On machinery it is not. The two categories behave differently.

Deferred cosmetics wait. Deferred maintenance accumulates inside the machine.

• Lubricating oil does not simply get dirty. Its additive package is consumed. Once depleted, the oil continues to circulate and to look like oil while no longer protecting bearing surfaces as intended. The wear that follows is gradual, cumulative and entirely internal.
• Coolant is a chemical system, not water. Corrosion inhibitors deplete on a schedule of their own. When they are gone, internal corrosion and cavitation erosion proceed quietly in passages nobody can see, on a machine that starts and runs normally.
• Filtration protects components far more expensive than filters. Fuel filtration exists to keep injection equipment alive. Deferring it does not produce a dirty filter. It produces wear in the injection system. That presents much later and costs a different order of money.
• Raw water circuits foul progressively. Heat exchangers and charge air coolers lose efficiency long before they fail. The machine then runs hotter than it was designed to. That is itself a cause of damage.

In every one of those cases the equipment continues to present well. It starts, it runs, it makes the right noises, the space around it is clean. The consequence of the omission has been deposited internally and will be paid for later, by whoever owns the vessel at the time.

Running hours are a claim, not a fact

Buyers are trained to look at the hour meter. Sellers know it. An hour meter records what it was connected to, for as long as it was connected. Meters are replaced during refits and after failures. The replacement starts wherever it starts.

The number is not useless. It is simply not self-supporting. The question worth asking is not what the meter says. It is whether what it says is consistent with everything else. The maintenance intervals recorded against it. The wear visible on the machinery. The fuel and lubricant history. The story the vessel's operating pattern tells.

A figure that no other record corroborates is a figure, not evidence.

Low hours are not automatically good news

This surprises buyers more than anything else in this subject. Manufacturers specify maintenance in elapsed time as well as in running hours. Their reasons apply with full force to a vessel that has been sitting.

Lubricants and coolant additives degrade with age whether or not the machine turns. Seals dry, take a set and leak when they are eventually asked to work. Fuel deteriorates in the tank and can support microbial growth at the water interface. Unused machinery corrodes internally from condensation. A cold engine room breathes. Batteries sulphate. Systems that are never exercised seize quietly.

A yacht with modest hours and a complete calendar-based maintenance history is an excellent prospect. A yacht with modest hours and no maintenance history at all is a vessel that has been ageing without being looked after. The low hours are not the reassurance they appear to be.

Which machinery the record matters most for

Attention naturally falls on the main engines. On a yacht used as yachts are actually used, the generators frequently accumulate far more running time than the mains. They carry the hotel load whenever the vessel is occupied, at anchor and alongside. They are among the hardest worked machines aboard and among the least discussed in a listing.

The same reasoning extends across the vessel. Stabiliser and steering hydraulics, air conditioning plant, watermakers, sewage treatment, fire and bilge systems, deck machinery, cranes and tender handling gear all carry maker-specified maintenance. All deteriorate when it is not done. None of them announces the omission until it is asked to work.

What a good record proves. What it does not

A well kept planned maintenance system is a strong signal. Tasks closed against dates, parts identified, work attributable to named people or yards, intervals respected over years rather than in the months before a sale. It suggests a vessel that has been managed rather than merely used. It raises confidence materially.

It does not replace inspection. Records can be optimistic. Work can be recorded as done and done badly. A properly maintained machine can still develop a fault. The record and the physical examination answer two different questions: how the equipment has been treated across its life. What condition it is in today. Neither substitutes for the other. A survey resting on one alone is half a survey.

What a thin record tells you

A record that begins recently on a vessel that does not is worth understanding rather than dismissing. There are ordinary explanations. Management changed. A new captain rebuilt the system properly. Files were lost when a company was wound up. Records were kept ashore by a manager who is no longer engaged.

There are also less comfortable explanations. The honest position is to set out both. The proper response to a gap is to report it plainly, along with the plausible reasons for it. Then to be clear about what it prevents anyone from concluding.

Where the record cannot be reconciled

Sometimes the accounts do not agree. Recorded hours do not match the maintenance intervals logged against them. A refit history describes work that the machinery does not show. The vessel's operating pattern implies use the record does not reflect.

At that point the examination moves to whatever independent trail exists. The most useful one is usually procurement. Maintenance consumes parts. Parts are bought. Filters, elements, impellers, anodes, belts, lubricants and service kits leave a purchasing record that is harder to keep consistent with a false account than the maintenance log itself.

Where the procurement record cannot be reconciled either, the correct conclusion is not that the machinery is bad. It is that the condition of the machinery cannot be established. That is an honest and important finding. It is also a different species of problem from a defect that has been located and costed. A defect has a price. An uncertifiable machine has a range. The buyer is holding unquantified risk rather than a known cost.

What follows is a decision rather than a negotiation. The risk can be priced, it can be investigated further by opening or testing the machinery. Or the purchase can be declined. It cannot be resolved with a repair quotation. Nobody yet knows what would be repaired. We have written elsewhere about what happens once defects are found. This is the case that sits outside that framework.

What to ask for and when

Ask before the survey rather than after. The records determine what the physical examination should concentrate on. A reluctance to produce them is informative in itself.

• The planned maintenance system in full, rather than a summary prepared for the sale.
• Running hours logs for main engines, generators and significant auxiliary machinery.
• Refit and dry dock history, including the scope of each visit and not only the dates.
• Class records, where the vessel is classed, together with any outstanding conditions.
• Where the accounts do not reconcile, the procurement record for machinery spares.

A buyer who has these before anyone boards is in a substantially stronger position than one who receives a report and starts asking afterwards.