Buying a boat can be expensive, even before you pay for the boat. You are shown a boat, decide whether it is a candidate and then have a closer look.

You might even go for a second look with your partner, but eventually it comes down to making an offer, subject to survey. The boat is hauled out, the surveyor finds all sorts of problems, and you decide to keep looking.

You do not get much change from a grand after paying for the survey, even on a smallish boat. But you do have the all important documentation that helps you decide whether to proceed with the purchase. Trouble is, this scenario can
be repeated several times before finding the right boat.

One surveyor I spoke to during research for this article had surveyed nine boats for the same client, before suggesting he change focus to a different design. The expense adds up, which is why I am suggesting you do your own pre-survey assessment.

If you are even the slightest bit practical and/or experienced, you can avoid the multiple-survey trap. In this article, I hope to guide you through the steps and pitfalls in performing a pre-survey assessment. I focus on fibreglass boats, because they are the most popular but, apart from my comments about the hull and deck construction, this content applies to all yachts.

What do you need?

The idea is to rule in or rule out the current boat of interest. Your assessment in no way replaces a professional survey, which you will probably need for insurance purposes anyway.

Regardless of insurance, you will usually save the surveyor’s fee in negotiating the correction of defects before the deal goes ahead. Even if the boat is near new, a diligent surveyor is likely to find a few issues.

I repeat, doing your own pre-survey assessment is not a substitute for a pre-purchase survey. It is to save you from the need to professionally survey every single boat you are seriously interested in.

The requirements for doing your own pre-survey assessment are simple: a couple of hours’ access to the boat, an enquiring mind, close observation and a collection of simple tools you probably already own. The photo above shows the gear I take along. See also sidebar: ‘Tools you will need’.

It makes sense to carry it all in a small bag. The bag lets you keep all your stuff together and private as you move through the boat. Owners and brokers can be nervous about people approaching boat inspections with a bunch of tools in hand.

Some surveyors use binoculars for checking the rig. I deplore this practice, because it only gives a false sense of security. A survey report claiming “the rig appeared in good condition” tells you exactly nothing if the fine print reveals that the rig inspection was conducted from on deck.

You cannot detect small, potentially fatal cracks and other defects in a mast from deck level. If you must do rig inspections from the deck, use a camera with a powerful telephoto lens. The right camera can be useful for this, but until drones can be flown in for close-ups of every part of the rig, it is still best for someone to go up there. For more information about how to conduct your own rigging survey, see the section further along on rigs.

Other useful tools are: ice cream sticks, easily available in the craft section of hardware stores, to check for rust inside coolant reservoirs and heat exchangers; paper towel for checking oil levels and consistency; plus a pair of throwaway gloves to protect your hands when poking round engines and bilges.

A notebook and pen round out the list, although I prefer to just photograph everything and not make notes at all. This stems from my background surveying rigs, where a notebook and pencil can be inconvenient.

Apart from all of the above, the most important tools are your eyes and a healthy cynicism about the causes of stains and leaks.

The boat

You need to record the details of each boat, if only to delineate where the photos for this particular boat begin amongst a series of similar photos of other boats.

With rig surveys we always took a photo of the name before stepping aboard. This may be all the identification you need, but a record of hull and registration numbers might be handy later. You will need to check ownership, encumbrances, registration and so on if the sale proceeds.

The survey

Let us say you have already looked at a potential buy in terms of how well it suits your requirements and taste. Time to put on your surveyor’s cap.

A boat assessor needs to think like a detective. If something seems amiss, we need to consider why. See a problem on the outside? Check inside that area for damage.

Take a slow look at the overall condition of the boat. Consider how well it has been looked after. Sloppy maintenance, lack of maintenance in one area like the engine, or unrepaired damage, indicates the owner’s general attitude.

If there is a maintenance log, have a careful look at it. Was the maintenance preventative, or done after something broke? Look for recurring issues. The mere existence of a genuine maintenance log is usually a bonus and can be proof of a well-cared for boat.

I don’t necessarily conduct a pre-survey assessment in any particular order, but prefer to start by checking potentially deal-breaking items. Finding them early saves time and effort. However, in the absence of major deal breakers, it pays to work logically to ensure you do not forget anything.


Walk or row around the boat and look carefully at the hull, with and without your sunglasses. Slight changes in colour, lifting paint, or overspray could indicate repairs.

Repairs are not necessarily an issue but, if poorly done or denied, could be a problem. Flat spots or waves in the topsides may signal incorrectly fitted chainplates or bulkheads.

Is the hull shiny, or dull and chalky? If the gloss is gone, does it need a good cut-and-polish costing hundreds of dollars, or a repaint costing thousands?

Rust streaks in line with stainless steel fittings indicates deterioration, probably due to crevice corrosion. Stainless steel needs oxygen to form a passive non-rusting surface. In places like where the chainplates pass through the deck, oxygen is unavailable but, if the metal is not kept dry, crevice corrosion can occur.

This is the most common reason chainplates fail. Chainplate failure usually equates to dismasting, so you need to take it seriously.


Whether or not the boat has cored construction in the hull, the decks of post 1970s boats will most likely be cored with either foam or end-grain balsa. These should have solid areas where hardware is attached, so look for any add-ons or any sign of the fastenings crushing the deck.

One way to tell if you are dealing with a cored deck is to look underneath, at the area where it meets the hull. This may only be visible inside lockers, especially the cockpit lockers.

On most cored decks, you will see a step where the laminate changes from solid fibreglass near the outer edge to the thicker cored area. You may also be able to tell by looking around ventilators and hatches, although these usually have a trim piece to hide the cutout.

Any deformation or leak is a point of entry for moisture to travel within the structure.

Does the deck flex when you walk on it? You may be able to see leak points from below, but the best way to check for soft spots is by tapping gently with your small hammer. If you practice this beforehand, you will be familiar with the difference in tone between solid and soft material. What matters here is the change in sound, rather than becoming expert at knowing exactly what the hammer is telling you.

A soggy deck (or hull if the hull is cored) could mean expensive repairs. This can be a deal breaker when the cost is deducted from the asking price.

While you are on deck, check all the lifeline stanchions, pulpit and pushpit for cracks and general security. Look for depressions where a stanchion base has been pushed into the deck, potentially allowing moisture to enter. If the stanchion bases are cast aluminium, check for cracks where the stanchion enters.

Do the cockpit locker lids seal when closed and the hinges lock smoothly?

Try the helm. Is it smooth and easy to turn, without unreasonable play? For wheel steering you will need to look below at the quadrant and steering ram or wires.

Does it have provision for an emergency tiller? If the rudder post comes up through a tube in the hull, what would happen if the rudder hits something and breaks the seal between hull and tube? Some boats have a bulkhead here to prevent major flooding, on others, a rudder tube break could sink the boat.

Teak decks

Lovely to look at and walk on, but a major headache as they age. Can also be a deal breaker as the cost of repair can be high.

Older teak decks are screw-fastened to a fibreglass or plywood sub-deck. Literally thousands of screws are each a potential leak point. Look for lifting or missing bungs as an indication of how much the teak has worn.

More recently, teak decks are simply glued on, which eliminates the leak problem. However, you still need to assess the condition of the teak. If the timber is worn into valleys between the lines of sealant, you will need to ascertain how much thickness remains.

Removing a worn teak deck is both time-consuming and expensive, as John Tylor explained in CH June 2016.

Port lights/windows and hatches

To test the integrity of hatches and port lights, hose the boat down enthusiastically and check inside. If the owner or broker will not allow this, you can bet it leaks somewhere.

The actual leaks are not the major issue here, as they can usually be repaired fairly simply. You are looking for damage caused by long-term leaks: rotten cabin sides; rot where the cabin sides meet the deck; rotted framing beneath the leaking area; rotted bulkheads and ruined soft furnishings can all be expensive to put right.

Have a look round the windows and hatches from inside for dark areas or delaminated lining material.
If they have been leaking, expect damage to the cabin sides, hull lining, head lining, and whatever lies directly below.

Are the aluminium frames corroded? Acrylic or polycarbonate lenses crazed? Aggressive sanding, then progressively finer grades of sandpaper followed by polish can remove light crazing. (David Bowden, CH June 2016). Sound time-consuming? It is, replacement is often more economical.

On opening ports that have the rubber gasket attached to the lens, try gently pushing the gasket to ensure it is attached properly. Most are glued on with contact cement, which breaks down over time.

Bulkheads, chainplates and the mast support

Look around the lower edges of bulkheads for signs of water staining, especially where a bulkhead is tabbed to the hull. Some boats have laminex-coated bulkheads, which is fine as long as the laminex has been removed where the bulkhead is fibreglassed. There are production boats in Australia where this was not done and, unsurprisingly, the glass has parted company or never adhered to the bulkhead.

Try sticking your knife blade between the two to check the bonding. Check all accessible bulkheads the same way.

Is the mast keel or deck-stepped? What is under the lower end of the mast or compression post?

This is a prime site for movement, which can be indicated by: rigging screws that have been taken up to their limit; by cracking around the mast base on deck if deck-stepped; movement of the floorboard supports and floorboards that do not fit properly.

Under the floorboards/keel attachment

Lift the floorboards and have a look at the keel bolts, especially in the area just aft of the keel. Actually, have the owner or owner’s representative lift the floorboards because these things are easy to chip. If you cause damage, you may be liable for the repair. The same goes in removing any parts of the headlining you would like to see under.

A hard grounding tends to push the aft end of a fin keel upwards. Check for signs of movement in the structure supporting the keel. In modern boats, this is usually a series of moulded sections running athwartships (cross-wise), which also form part of the internal furniture support or mouldings.

Rusty keel bolts or nuts are a serious warning signal. Rust comes from the break down of the bolts. Use your hammer to check the entire keel support structure, or pan, for soft-sounding areas that could indicate delamination.

General interior

Is the interior worn? Check under bunk cushions, mattresses and coverings for mould and moisture.

A musty or mouldy smell inside could indicate leakage, prior water damage, or simply neglect. However, lack of mouldy odour does not necessarily indicate no mould is present.


Check steering cables, quadrant, tiller, pedestal, autopilot. Is the steering free and easy to move, without excessive slop? Do the cables run fairly through their sheaves? Is the area generally accessible, or do you need to disassemble the aft end of the boat?

The latter could indicate nothing in there has been maintained or checked for a long time.


Rigging replaced over ten years ago, or no documentation at all? Your insurance company probably will not accept it.

Furler: unroll the headsail to see the condition of the sail and the furler foil. Pay attention to the point where the foil enters the drum. Damage here could indicate the furler has had a hard life.

Look up the foil. Is each two metre section of foil neatly mated to the one above, or can you see gaps? Is the foil track straight or twisted?

Check the boom gooseneck for wear, the sheaves at both ends for damage and then look under the boom. Current production boat rigs often suffer from corrosion under the stainless steel sheet and vang takeoffs that fit into a track on the bottom of the boom.

Check anywhere you see dissimilar metals, especially stainless on aluminium, for corrosion or evidence that anti-corrosion paste was used on assembly. I have already written about DIY rig checking (CH September and October 2013, or go to and search for: ‘on deck’ and ‘aloft’).

On deck you can check the condition and attachment points of lifelines and stanchions, pulpit and pushpit, chainplates and mast step, as well as the size and security of any mooring cleats. Do the winches turn freely? How long since the last service?


Comes with fifteen bags of sails? You can bet most of them are old and have been replaced.

The sales brochure expression ‘x bags of sails’ shows you have a lazy and old fashioned broker who has not bothered to find out what is in those bags. These fossils are also likely to refer to the forward cabin as the fo’c’s’le, as if yachts still have a stowage area forward for those fifteen bags of sails!

Ask to have the mainsail hoisted, or at least released from its cover. You may not be able to judge its shape, but if the cloth feels brittle it is probably replacement time. With sails it is not so much their age, as how much use and UV exposure they have had.

Most owners will not want you poking a sail needle into their sails, but this is one way to find out if the cloth is brittle. A triangle-section sail needle pushed through supple material will leave only a tiny hole as it pushes the threads in the cloth aside. In brittle cloth, you will hear and feel the fabric tearing and be left with a triangular hole.

Ideally, take spare sails ashore and spread them out, but if that is not practical you can get a fair idea of condition by looking at the corners, the material along the leech and both ends of the luff tape.

Should you be looking at a hanked sail, check the hanks work and are not corroded shut.

All lightweight and nylon sails can be checked the same way. Is the cloth crinkly or limp? Are the corners stretched? Are photos available to show that these sails actually fit the boat? An old trick is for owners to toss a few extra sails from previous boats aboard, to add to the perceived inventory.


Is the engine and engine room clean and tidy? Does it look like no one has been there for a long time, or is it suspiciously clean, as if someone has just done a big clean up? Freshly painted engines are a give away, especially if the rust has been painted over.

Look at the glass bowl fuel filter/water separator. Is the fuel clean, or can you see gunk or water in the bowl?

Pull the dipsticks for the motor and its gearbox. Feel the oil with your fingers. Is it gritty? Black or like honey? New oil can indicate fastidious maintenance, or a cover up job.

Any sign of water, moisture or corrosion on the dipstick could mean the engine needs a major rebuild. Wipe the dipsticks and your fingers on your paper towel.

Take the pressure cap off the heat exchanger. Stick your finger in there to see what the fluid is like. Any sign of rust, replace the cap and move on to the next boat.

Look inside the coolant reservoir. As with the heat exchanger, you should see translucent red or green liquid, not mud
or rust. The coffee sticks are nicer to use for this than your fingers.

Can you see evidence of access to the raw water pump? Fastening screws with their original paint and corrosion build up around the screws both indicate the impeller has been in place a long time. Not good. Impellers become brittle with time and should be regularly replaced.

Same story for the anode on the heat exchanger. If it has not been replaced regularly the heat exchanger may need some expensive attention.

Does the propeller shaft turn straight or is there a slight wobble, indicating a bend?

For a sail drive, find out if the rubber diaphragm has ever been replaced. Its service life is supposed to be five to seven years, but I am yet to see one replaced at that age.

Check the engine is cold and has not been started and run before you arrived. If it has, satisfy yourself about the reason.

When you start the engine from cold, does it have good water flow at the exhaust? Did it fire up willingly?

Check all the belts and hoses for wear. Rubber deteriorates with age, so low engine hours are no comfort here.

While you are in there, take out your hammer and tap the engine beds along the length. You should be able to hear if
the underlying timber is soft.

Move to the motor mounts and check they are the same both sides. A compressed mount on one side could indicate alignment issues. Are they fixed solidly or is there evidence of movement?

Hoses, skin fittings and seacocks

Locate as many through-hull fittings and associated seacocks as you can.

Try opening and closing them. Are they stiff or corroded? Hose clamps rusty? Rust coloured stains indicate rust coming from somewhere. Flex the hoses. Are they brittle or cracked? Skin fitting and seacock failure can sink the boat, so it is important they are in workable condition.

What is the composition of the through-hull and seacock? Is there a mixture of different metals, a variety of mismatched parts, plastic bits, or things covered with tape?

Are the hose clamps fitted correctly? It is not uncommon to see hose clamps fitted too far along the hose, where they cannot clamp the hose to the tail. Often this is because domestic hose tails, like those cheap ones from the hardware store, have been used.

The tails on these are often too short to take the two hose clamps recommended for below waterline fittings.

Are the through-hulls and seacocks bronze or brass? Brass can be identified by its smooth finish and bright golden hue. Bronze is a dull gold colour, often left in its sand-cast finish state because it is difficult to machine.

Look at the hose clamps. Are they strong, or the cheap, slotted type that break readily. As with other fittings on the boat, the quality of hose clamps used can indicate the general quality of the full fit-out.

Some hose clamps, marked as stainless, have mild steel screws that will rust and fail. Use your magnet to identify them.

Those massive-looking t-clamps can be excellent, but are no guarantee of strength. Apart from the vulnerability of the spot welds, if not assembled with grease or Tef Gel, the threads can gall, which can cause the tensioning bolt to break. But, overall, they are a much better choice than the slotted type. If kept dry, corrosion of the spot welds should not be an issue.

If you happen to be inspecting the boat out of the water, make a note of all the skin fitting locations, then go up and find them inside. Make sure they are all accessible. It is not unheard of for skin fittings to be hidden under mouldings, machinery or pipe work.

Bilge pumps

If the bilge is clean, test that each pump actually shifts water. The motor whirring on an electric pump is no guarantee that it works. Please do not try this if the bilge is oily. There are heavy fines for disposing of oil overboard. This is why boats should have a pan under the engine – to collect any leakage before it joins the bilge water.

Look carefully at the diaphragm of manual pumps. It is no big deal to replace one, but you need to know if it’s perished.

Are the pumps protected by strum boxes or built-in screens to prevent sucking up the sort of rubbish that stops them working?

Remember the shower sump pumps too. These should be easily checked for operation by running the shower for a few minutes.

Gas appliances

Does the boat already have a gas compliance certificate?

Rules are evolving, so what may have been legal before may not be acceptable now. We once looked at a newish imported boat that was advertised as never having had the stove used. We soon discovered the gas system had never been connected because there was no way it would comply with Australian regulations.

One of our own boats had the gas system removed on sale. The rules had changed since our purchase and the gas locker was no longer legal. It was now considered too close to an opening port in the cockpit.

You will need to familiarise yourself with your state rules before you can make any judgements on the likely legality of the system. However, anyone can look at the general safety of the installation.

All gas bottles must be vented overboard, not into the cockpit unless it is self-draining and has no openings to the interior. The bottles must be a set distance from any openings into the hull, well secured, in date, and not rusty. Hoses
must be in good condition, not chafed, perished or worn. Copper pipes should be well secured and not corroded.

Follow the supply line through the boat to ensure it is not pinched anywhere, or chafing, particularly where it passes through bulkheads. Try the stove burners and any other gas-fuelled appliances to ensure they work.


Ideally, the refrigeration will be turned off when you arrive at the boat. Have it switched on and then check it is cooling. These days many people leave electric fridges running at the marina, so this check may not be possible. If it is a eutectic system, check drive belts and compressor mounts, notorious failure points.

Especially if the fridges are always on, check for rot in the cabinetry around them. This is often caused by condensation keeping the area damp.

Do built-in cabinets have sufficient insulation? For the northern parts of Australia look for at least five centimetres, preferably more, plus lids that are insulated and seal properly.

Electrics, electronics, instruments

Ask to see all electrical components switched on and working. You may not be an electrical genius, but untidy wiring is a sure sign of amateur electrics or additions.

Are the electronics current? I recently inspected a boat that still had an operational Magnavox satellite navigation unit, which was of course completely useless since the transit satellite system was phased out sometime around the 1980s.

A more likely discovery is the chartplotter with out of date chart card. These can easily be replaced, but at a cost.

Are the batteries secured and ventilated? How old are they? Battery banks on modern yachts are an expensive item to replace.

Toilet and shower

Look for evidence of leakage at the base of the toilet and around its hoses. Does it smell when flushed? Lingering odour may indicate the hoses need replacement, or simply that it has been sitting unused with seawater in the hoses.

The first flush could be inconclusive, but keep trying. If it still stinks, suspect the hoses. Leaks could indicate that some of the gaskets may be failing.

It is sometimes cheaper and definitely more pleasant to replace the entire toilet rather than take it apart for overdue maintenance. If the toilet is leaking, check the base it sits on for rot or delamination. Check for the same in the shower sump and surrounding bulkheads.

Anchor winch and ground tackle

Look for rusty chain, the worst part will be at the bottom of the pile, plus anchors, corrosion where stainless shackles and swivels have been attached to galvanised chain and the condition of the winch itself.

Ask for a demonstration.

Check the motor under the winch. These are often badly rusted and/or corroded, however some dreadful looking winch motors perform perfectly so do not be too concerned if the rest of it looks okay.

How much fall is there for the chain as it enters the chain locker? It is preferable not to need someone below stacking the chain as the anchor is raised. A locker with insufficient fall will result in a chain pile that will fall over and tangle when the boat heels over.

Poor chain storage is not necessarily a deal breaker. Some otherwise excellent boats suffer from this problem. However, you need to be aware of the need to knock the pile down before it falls over.

Dinghy and davits

Is the dinghy suitable for your intended usage and the size of the boat?

Are the davits secure and adequate for the weight of the dinghy? Is the hoisting arrangement practical for the strength
of you and your crew?

If the dinghy is inflatable, look at the condition of the sponsons and the transom/sponson or hull/sponson joint. Are the lifting handles, d-rings, and seat holders secure? Does it have chaps protecting the sponsons? Does the outboard start easily?

Safety gear

Flares and EPIRB in date?

Check the age and service status of the liferaft, if there is one, plus the fire extinguishers.

Auxiliary items

Things like fenders and mooring lines are more than handy, but expensive to add. Check they are suitable and in reasonable condition.

Other extras that are expensive or time consuming to add include awnings, biminis, dodgers, hatch wind socks, boarding ladders, insect screens, side screens or clears for the bimini, a cover for the dodger screen, curtains, deck wash system and even a transom shower. All these add value if they are appropriate and in good condition.

Documentation generally

If the seller is claiming new items, or service expenses, ask to see invoices. I have found that time is elastic for some boat owners who may claim something is new when it is in fact several years old.

Less common are owners who deliberately deceive, showing copies of quotes for work that was not actually performed. Look at the invoices, check the dates and that they relate to the boat you are on.

Is there a maintenance log? Evidence of regular maintenance is gold, showing not only that the boat has been looked after, but that the owner cared enough to document what was done.


Your pre-survey assessment is unlikely to include a look at the bottom, unless the boat is already hauled out. However, on older boats the likelihood of osmosis is quite high.

On these boats, it is more a question of whether the blisters have been repaired satisfactorily or just filled. A proper job involves removing all affected material and then drying the hull, which is an expensive exercise.

Just opening, draining and drying blisters before filling with epoxy is temporary at best. Being a much cheaper option this is a popular choice, but a boat treated in this way is an ongoing project.

For an idea of what is involved in a proper repair, have a read of Wendy Sears’ article Tackling Osmosis (CH March 2016). I will not go into detail about osmotic blistering here, as there is way too much information to cover.

I suggest that whether or not you are concerned about osmosis, you should buy Paul Stevens’ ‘Surveying yachts and small craft’. It is worth the price just for the information on osmosis, but is recommended for all amateur surveyors of recreational craft.

Your summary

By the end of your inspection you will know if this boat is worth pursuing.

If you still want it despite the defects you have found, you will need to estimate the cost of putting it right. Even if you cannot find much wrong and think the boat is a goer, remember that a professional surveyor may discover much that you have missed.

In both cases, you probably have not had the opportunity to inspect the boat out of the water. The condition of the hull and appendages will need to be assessed before proceeding.

In addition, consider separate inspections by a diesel mechanic, a marine electrician and a yacht rigger. Most marine surveys do not include the engine, electrics or rig.

These extra inspections may be costly, but may also save you money, either in the prepurchase negotiations or afterwards.

A good insurer will be impressed that you have taken the trouble to do a full assessment of the boat’s condition.

Having performed your own inspection, you are either much more familiar with what may become your next boat, or have saved yourself the cost of a professional survey for a boat you do not want.

If you plan to go ahead, please remember that a professional survey will still be required. The surveyor is likely to find far more defects than you could, which will add to your negotiating power.

Most insurers require a survey before issuing a policy, so even if you feel a survey is unnecessary, it is better to pay for one before the purchase, rather than afterwards. A professional survey is usually worth more than its cost, even
if just for peace of mind.

Petrea McCarthy
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