The Pre-Purchase Survey (sometimes called a Full Condition Survey) is the most comprehensive type of survey available and we strongly advise you order one when purchasing a used vessel.
Because our surveyors are also qualified and highly experienced marine engineers we're prepared to include a free Engine and Systems Survey with a Pre-purchase Survey at no extra cost.
We strongly recommend that a Sea Trial is conducted as part of your Pre-Purchase Survey. We believe it's an important part of evaluating a vessel; its engines, its systems, how it handles and its overall performance.
When you want to insure a boat, or renew your existing insurance policy, your insurance company will need an Insurance Survey in order to determine the condition and fair market value of the boat.
A Valuation Report frequently comes as a standard part of another type of survey; our Pre-Purchase Surveys, Insurance Surveys and Financial Surveys can all include a Valuation Report.
Financial Institutions often lend money against the security of a yacht or powerboat and when they do they need independent verification that the vessel is in reasonable enough condition to justify the amount of money being loaned.
“I just wanted to thank you for the brilliant job you did on my pre-purchase survey. Your patience, flexibility and accessibility were greatly appreciated. Your attention to detail and thoroughness surpassed every expectation I had. On a side note, even the insurance company made mention that this was the "most comprehensive survey we have ever seen". Thank you for making this part of the buying process less stressful.”
We are building up a list of interesting articles and pieces of advice written by our surveyors that we hope will be of help to yacht owners and prospective buyers.
What is Osmosis? Osmosis is coursed by a chemical-physical reaction, that takes place during the migration of a solvent, in this case water, through a film separating two liquids with different salinity concentration.
What does this mean for boats? First, water migrates through the boats laminate hull to create and then fill blisters; water will then start to solve every material it can: glass fibers, undercured resin, etc. At the end of this reaction, the new solution will attract more water through the gel-coat, so that the pressure inside the bubble will grow and expand.
The reaction will continue as long as the boat is in the water; the blister that at the start of this reaction can start out very small measuring 3 to 4 millimeters in diameter, but they will increase in-size due to the inside osmotic pressure, with time and permanence in the water. Once this reaction is started, the osmotic process will continue without any possibility of stoping or slow down.
Osmosis is a ongoing problem which does not stop or reverse by itself unless the hull is kept out of the water; even then, and after months of being on the hard standing, the liquid may be present in the laminate and, due to the fiberglass' permeability, it will move along the fibers. This is why, after a wile, bubbles appear smaller due to reabsorption.
This reaction is sometimes unfairly used when selling a boat with osmosis, the boat will be kept ashore and sheltered for some time until the blisters are smothered because the liquid inside them has now spread over a larger area and also, the antifouling coating has become uneven thus hiding blisters and others defects.
The only way therefore to see if a boat, ashore for some time has osmosis, is to check the hull's humidity with a moister meter and taking samples of antifouling coats. Care and attention must be exercised during these tests since humidity alone may not mean osmosis: for this to be present, bubbles must be liquid filled. Gel-coat osmosis blisters will be liquid filled while humidity absorbed by a hull is not an osmosis generated symptom.
Identifying Osmosis The bubble should be round this is due to the internal osmotic pressure which is constant in all directions, the bubble will deform the gel-coat surface: the bubbles might also be located between different antifouling layers, while the underneath gel-coat is good after sanding. In this case it is an antifouling defect only, and there is some solvent or water between the plies. This can happen when plies are painted too quickly so the paint dry dose not dry out completely, or when a ply wood is painted on a wet hull some humidity can be enough to course problems or when antifouling is not properly thinned.
A simple but effective way to asses bubbles are with your nail: if it brakes easily this is more than likely just an antifouling defect, since it is impossible to break the gel-coat with nails, and a center-punch or a knife is needed to penetrate gel coat. Its important to be able to recognize the difference because it is commonplace to find bubbles on the hull which are not osmosis generated.
Another requirement for a bubble to be classified as osmosis, is that it must contain liquid. It may be just a drop on a small bubble, but will be a lot on a large one (say more than 2 centimeters in diameter), to the point that water will leak out when the blister is punctured. The liquid contained inside will always have an acetic smell and will feel smeary on touching. This is because in a bubble is filled with osmotic liquid, the polyvinyl clorure which is around glass fibers is converted by the osmotic process into polyvinyl acetate with a characteristically strong acetic smell. Another characteristic of blisters' liquid, its always smeary and, it changes color with the passing of time: in a small bubble the liquid has always a bright yellow shade while on the larger ones is darker until it become almost black in the most serious cases. Is there a relationship between blisters diameter and osmosis' age.
Marine Diesel Engines Marine diesel engines are a strait forwould and relatively simple piece of equipment in how they operate, and are among the more basic of the engines out there.
Compression The pistons compress air in the cylinders, and the more the air that is compressed the hotter the air becomes. When the piston is near the top of its stoke or top dead center, diesel is (Injected) into the cylinder and compressed, superheated air ignites immediately, raising the temperature and pressures even higher, which drives the piston forcefully back down the cylinder.
Diesel Engine Temperatures Diesels are sometimes called compression ignition engines. They do not have a true ignition system like that of a petrol engine. The diesel fuel is ignited by the extremely high temperature generated by compressing the air in the cylinders. A diesel engine will not run if the air does not reach the correct ignition temperature.
Air Filters and Air Flow Gaining the correct ignition temperature, the engine also needs a good supply of clean air and correctly timed and atomized injection of fuel dispersed into a mist of particles. A diesel with a poor air supply will produce poor combustion, causing the engine to loose power, overheat, and put out black smoke.
A poor air filter restricts airflow through the engine, demotes performance. A poor condition air filter will allow tiny particles of derbies through into the engine its self. The derbies become embedded in all the soft metal surfaces inside the engine, such as pistons and bearings, increasing engine wear and shorting the life span of the engine. Once embedded the derbies are near to impossible to remove, no amount of oil changing and flushing will resolve this problem.
Smoke? What to look out for Diesel engines should admit as little smoke as possible, with the possible exceptions of Acceleration or heavy loading such as towing another boat. The engine may give off black smoke for a second or two until it settles down.
Idling or running the engine under low loads. The fuel pump may have problems measuring out the small quantities of fuel being called for, resulting in an uneven idle and a little smoke.
Black Smoke Black smoke is a result from poor combustion of the injected diesel fuel. Other possible related issues stem from restricted air flow through the engine. Check the air filter first if the engine has a turbocharger, check all the ducting for air tightness. Remove the inspection cover and check the compressor assembly for carbon build up. If you find build up, clean the assembly, making sure it spins freely with no binding. Open up the exhaust line for any kinks or other restrictions.
Dirty air filters, defective turbochargers, the exhaust system could be restricted in air flow from a blockage or collapsed exhaust pipe, too much fuel injected (generally due to overloading-the governor responds by opening up the fuel rack and pumping in more fuel). Improper fuel injection (an injector fails to atomize the fuel correctly, dribbles fuel into a cylinder after the main injection pulse, or injects to late).
Blue Smoke Blue smoke comes from the burning of oil. Oil can find its way into the combustion chambers-up past the oil retaining ring; down valve stems; through defective turbocharger seals; and out of crankcase vents, A high crank case pressure as a result of defective oil retaining ring which is on the piston its self.
White Smoke White smoke usually means the cylinders are misfiring, water or air in the fuel, or water in the cylinders (most likely from a faulty head gasket or cracked cylinder head). If the smoke appears on start up and at light loads but clears when the engine warms, it maybe due to condensation formed in combustion, If the smoke develops during normal operating, generally accompanied by misfiring, the engine is running out of diesel or has water in the fuel.
Overheating of your Engine Seawater is circulated directly through the engine or heat-exchanger. Engines with heat exchangers have an enclosed “freshwater” cooling circuit with a header tank. The cooling water passes through a heat exchanger, which has sea water on its other side, carrying off the engine heat.
Heat exchangers are either inside the boat, complete with their own raw water pump, or fitted to the outside of the boat in direct contact with the seawater (called a keel cooler and quite common on the old Broads cruisers) and so requiring no raw water pump.
Almost all engines with a raw water pump and circuit pass the raw water through any oil coolers (in the engine and hydraulic gearbox, if fitted) and then discharge it into the exhaust to cool and silence the exhaust. Even some keel cooled engines have an extra raw water circuit specifically to cool the engines oil and exhaust.
Overheating during normal operation Check the oil level. If a low oil level is causing the engine to over heat this should be addressed by increasing the oil level. The oil level should be checked regularly and toped up when needed.
The raw water inlet screen (if fitted) on the outside of the hull may be blocked with a piece of plastic. Throttle down, put the boat in reverse, and throttle up. With any luck the reverse propeller thrust will wash it away. Check the raw water filter. If there is a lot of debris/silt, the heat exchanger (or engine itself on raw water cooled engines) may well be silted up. Many heat exchangers have removable end caps and can be rodded out with a suitable wooden dowel.
The thermostat may be malfunctioning (some raw water cooled engines don’t have thermostats). Take it out and try operating without it. To test put it in some water and heat it. All raw water circuits should incorporates Zinc sacrificial anodes to help detract corrosion. They must be replaced at regular intervals.
Engine oil Analysis what is it? It gives you a snap shot of the engine oil condition on the day that the test is carried out.Oil analysis testing was traditionally used in the commercial field but now it is commonly used in the leisure industry.
The way oil analysis is now being sold is as a long term prediction tool. Wear patens of your engine can be mapped by the amount of oil top up you are using along with the amounts of fuel being burnt and a detailed picture can be built up of the condition of the engine. How much of your fuel ends up in the engine sump' because of excessive idling or poor fuel injection.
Oil Analysis Identify at early stages mechanical issues, which may in the future cause engine or equipment damage.
Provide added value to future boat sales, an engine condition report along with service details shows that the currant owner cares about the condition of there boat. Oil Analysis may help to avoid the need for a major engine repairs.
Taking an oil sample from the boat witch you are looking at buying could provide you with valuable information, showing up potential major issues with the boats engines. Oil analysis shows up the different types of metals that are found in the oil such as those from bearings, pistons and liners or valves. If the engine is showing high amounts of metals then action should be taken to avoid the need for repairs. Also oil additives and viscosity can be checked.
Oil Change Modern diesels run faster, hotter, and at higher pressures than older diesels. They generally have smaller oil capacities, a smaller amount of oil is working much harder. Diesel engine oils are specially formulated to deal with the tougher operating conditions, but even so must be changed far more regularly than petrol engine oils. Failure to carry out oil changes will lead to a build up of carbon sludge, dirt and acids in the crankcase; thus build up is difficult to remove even after re-peated flushing.
The air system comprises both the inlet and exhaust side of an engine. Any obstruction in either side will interfere with the air and gas flow through the engine, thereby reducing performance. Some engines do not have an air filter, but most do. Where fitted, the filter needs checking periodically. Just as with a car, it is not possible to lay down hard and fast rules on when to change a filter element-in dusty environments, filters need replacing regularly, but in most marine environments, changes will be rare.
When an engine is used for long hours at low loads and engine speeds the exhaust system will coke up over time. This may happen quite rapidly. Periodically the exhaust pipe or hose should be broken loose from the exhaust manifold or turbocharger and inspected. If carbon is building up to more than a light coat, the whole exhaust system will need cleaning.
Fuel Systems and Maintenance The fuel, even if clean when taken onboard, can become contaminated in the fuel tanks. Moisture from the environment condenses and mixes with the fuel. Bacteria can also grow and live in diesel, so its advisable to take regular samples from the bottom of your tank, either via a drain or by inserting a pump through the top of the tank. If water is present, the tank should disposed. If bacteria are present, the fuel will smell and there will be slimy deposits on the tank sides and in the filters.
Any good diesel fuel system setup will have two filters-a primary filter mounted between the fuel tank and the engine, and a secondary filter mounted on the engine between the fuel lift pump and the fuel injector pump.
The primary filter is designed to remove water and larger particles from the fuel; the secondary filter should catch any remaining microscopic dirt particles and suspended water droplets.
Close tolerances in the design of all fuel pumps and injectors, any amount of dirt can course problems. If from the start the owner gets rid of dirt and water in the fuel system, then most potential engine problems can be avoided.
Marine Batteries The main causes of problems with that of marine batteries is the wrong type of battery being used, the wrong size, or that of poor quality from new. You need to make sure that the boat battery being used is up to your boats requirements, anything less than that of what the boat is specified for should not be used, it might work for a short period of time but is likely to let you down just when you need it most. A good quality marine battery does not come cheap, and a lot of boats out their are sold with the lowest quality battery the retailer can get away with. This is not always the case, but always check the quality of the boat battery when buying a vessel, and ask for an upgrade if not.
Electronic Battery Chargers The electronic boat battery charger the prevalent type these days virtually eliminate the risk of that of overcharging the battery. They provide a 3 stage charging routine and use electronic sensors to manage the charging process of the battery to prevent the boat battery from being overcharged. An old electric charger may well be the cause of damage to your marine cycle battery if you are experiencing power problems. Unusual battery fluid loss and a hotter than usual battery rate are likely signs of overcharging.
Boat Battery Design The marine battery is at the heart of the electrical system of all Yachts and Powerboats. Most boats have a strait forward 12 volt DC set up. The marine battery is usually set up in a bank of one, two, three, or four industrial batteries which are connected in parallel. A larger vessel may have a 24 or 36 volt marine battery system. Usually, each battery is used to start one engine, but it is also wired to a battery selector switch. This switch may be marked 1, 2 ,or all. The selector switch controls which battery bank runs the house system.
The boat battery parallel switches is used to join two batteries together which results in a doubling of amperage but not a doubling in voltage. If both batteries are low in power they may start an engine that fails to start on a single bank but this is not always the case, the need to ensure that marine batteries are well charged and in good condition is essential.
Marine Battery Types There are a number of types of replacement lead acid sealed batteries Automotive or Starting batteries, Both marine cycle batteries and deep cycle batteries are all designed to different standards. A good quality deep cycle batteries have extremely thick plates, and are much heavier duty than the hybrid pseudo deep cycle batteries that are often found on sale or for use as golf cart batteries. In fact, the thickness and composition of the battery plates are the main factor to cost.
Cycling is the period of discharging and recharging the battery, and the life of a battery is determined by how many times the cycle takes place. An automotive battery is designed to withstand 5% discharges, whereas a deep cycle unit can withstand 50% discharges without sustaining long term damage.
The starting or automotive battery is often found on cheaper boats and are sold as marine batteries (sometimes called auto/marine). The problem here is that an automotive battery is designed to be constantly trickle charged by your alternator, so avoiding discharge rates or greater than the safe 5%. The sort of batteries marine vessels should use is likely to be a deep cycle battery, although hybrids are common.
The Deep Cycle Boat Battery The plates will be thicker than the automotive types but not as thick as a true boat battery. As discussed, marine deep cycle batteries can tolerate 50% discharge, your industrial deep cyclers can take an 80% discharge without permanent damage. An automotive battery will suffer permanent damage at these rates. So just because the boat battery you have is labelled auto/marine, don't assume that it is going to do a great job.
On this basis, it is important that you check the marine battery you have in your vessel and try to determine the quality of it. If in doubt replace it with a quality boating battery which should provide you with good, reliable service providing you give it the correct maintenance. Taking a chance with a boat battery is a bad idea, so invest in the best.