Buying a Used Boat: What to Check Before You Commit

A used boat is really three purchases at once: a hull, an engine and a trailer. Each can be sound while another is quietly worthless, and the one people inspect most carefully is usually the one that matters least. Here is the order we would look at things.

What should you check when buying a used boat?

Start with the principle that saves the most money: the shiny things are the cheap things. Upholstery, carpet, paint and a clean cover are all fixable for known amounts. Engines, drives, transoms and stringers are not. Inspect in the opposite order to the one your eye wants to.

The engine

Get the model and serial off the plate before anything else — it identifies the engine's real age and lets parts availability be checked, which for older engines is part of what you are buying. Our guide to reading your engine's ID plate covers where to find them.

Then look at the oil. On the dipstick you want oil, not milky coffee — a creamy emulsion means water is getting in, and that is a serious finding on any engine. Check the drive or gearbox oil the same way for the same reason.

Insist on seeing it start from cold. A seller who has warmed the engine before you arrive has hidden the single most informative thirty seconds of the inspection: how it cranks, whether it catches promptly, and what comes out of the exhaust at first. Watch the smoke, and our guide to what exhaust smoke is telling you covers what each colour means.

Then run it under load, in the water, for long enough to reach normal operating temperature and hold it. A great many faults — cooling problems, fuel starvation, overheating — only show up after twenty minutes of real work. A boat that cannot be sea-trialled is a boat bought on trust.

The hull and the structure

The transom is where sterndrive boats die. Press and probe around the drive mountings, look for cracking or movement, and be suspicious of any softness. Sound the hull and deck for soft spots underfoot, which point at wet core or rotten stringers, and get your head into the bilge with a torch rather than accepting a glance under a hatch.

Look at the whole bilge, in fact. Standing water, oil, rust streaks and a smell of fuel all tell you how the boat has been kept. On an older fibreglass hull, gelcoat crazing is usually cosmetic but impact damage repaired badly is not, so look for patches that do not match.

The drive and running gear

On a sterndrive, the bellows are cheap to replace and expensive to ignore — see our guide to sterndrive bellows for what to look for, and treat a set of unknown age as a cost you are inheriting. Check the anodes, which tell you how the boat has been maintained as much as how much protection is left. Look at the propeller for impact damage and at the shaft or leg for signs of a hard strike.

The trailer

The most-ignored third of the purchase, and the one that can strand you on the way home. Check the chassis for rust, particularly where members join and inside the rails. Jack a wheel and spin it to feel the bearings, look at the brakes and whether they work at all, and check the coupling, safety chains, lights and tyres — including the age of the tyres, which on a trailer usually perish long before they wear out.

Paperwork and the boring questions

Ask for service history and take the absence of it as information. Confirm the seller can actually sell it — that there is no finance owing — and check that hull and engine identification match the paperwork. Ask directly what has been repaired, whether it has been sunk or had an insurance claim, and where it has been kept, because a boat that lived on a mooring has had a very different life from one kept on a trailer under cover.

When to bring someone in

For a small runabout, a careful buyer with a torch and this list will do fine. Above that, a pre-purchase inspection is inexpensive relative to what it protects, and it is the same work we do for insurance reports and repairs — an unsentimental assessment of condition, put in writing. It is also useful when the answer is buy: knowing the impeller is due and the bellows have three years on them turns unknowns into a shopping list.

If you would rather buy something already checked, the boats we sell ourselves are listed on our boat sales page.

And if you have found something you like and want another set of eyes on it before you commit, ring 0412 532 984. An hour spent before the money changes hands is the cheapest hour in boating.