Yacht Buyer 5 Red Flags - What to check first?

🚩 Red Flag #1 — Is This Boat Legit?

Every boat has a Hull Identification Number (HIN). It might also be named as WIN or CIN, no matter the name of it, the boat needs to have one. If the boat is under 24 meters of length, the number should be carved or plated at the transom, or starboard side near the aft. Check if the number is visible, and compare to the one in the bot’s registry. It’s even better to find the hidden version of the HIN and compare.

🚩 Red Flag #2 — The Bilge Tells a Story

Similar to the general appearance from outside, the bilge tells you a lot. When looking at the bilge, another sense is also in action: what you smell tells you more than what you see.

A heavy toilet smell with no visible source means a black water system has overflowed and dried, possibly more than once. Standing water in the bilge means the boat is either taking water or leaking from a water tank. A boat with a permanently wet bilge has an owner who has learned to live with a problem rather than fix it. Salt lines mean the boat takes water which is pumped out time to time, again a problem you should not inherit. Oil droplets or wiped oil in the vicinity of the engine bilge almost certainly means engine oil leakage.

Also the appearance of the bilge structure gives us info of the boat’s possible repairs. Difference of bilge paint in means of colour or hue, any bulge or uneven surface, any rust or stains should put some question mark in your mind.

🚩 Red Flag #3 — Deck Hardware That a Magnet Will Expose

Every serious yacht buyer should own a magnet.

Touch it to every piece of stainless steel hardware on deck: cleats, stanchion bases, chain plates, sheet leads, winch bases, pulpit and pushpins and all fittings of those. True marine-grade stainless (316 or better) is weakly attracted to a magnet. Hardware that grabs the magnet firmly is not true stainless — it will rust, it will corrode, and if it is a load-bearing fitting under sail or in a storm, it may fail.

In my surveys I find non-stainless nuts, bolts, and fittings on deck hardware routinely — not occasionally. Especially the fittings of outboard engines. Sellers and brokers almost never disclose this because they either don't know or don't think it matters, but guess what: it does. A corroding chain plate holding the rigging that keeps the mast up is not a cosmetic issue. It is a structural one.

Also check aluminium spars (mast, boom) where stainless fittings are attached. Without an insulating buffer between the two metals, galvanic corrosion silently eats the aluminium from inside. White powdery residue at these junction points is the visible evidence — by the time you see it, the damage is already significant.

🚩 Red Flag #4 — The Hammer Test Reveals What the Gelcoat Hides

A GRP (fibreglass) hull inspection requires a hammer — specifically a bronze or hard plastic head mallet. Strike the hull firmly and listen to the sound.

A solid lamination returns a clear, resonant tap and the hammer bounces back. A delaminated or osmotic area produces a dull, dead thud — and the hammer does not bounce. This might be the sign of water has entered the fibreglass matrix, broken down the resin, and the structural layers have separated from each other.

The repair of any such areas in the hull is expensive (€3,000–15,000+ depending on severity) and time-consuming. A boat with significant osmotic delamination requires the hull to be fully dried using industrial heat equipment before any repair can begin, and then needs a full epoxy barrier coat application.

Still no deal breaker, there are no documented boats that just sank because of delaminated hull. What is a deal-breaker is some unrecorded repair at the hull for such an occasion. Unproper repair just makes things worse. A gel shield applied to a wet hull means the moisture being trapped in there, waiting to cause a worse situation. Ask for documented proof of the treatment: what method was used, which product, and when. If they cannot produce this documentation, assume the problem was painted over rather than solved.

On deck, gelcoat cracks that run in a pattern — star-shaped or following a structural line — are not cosmetic. They indicate the deck is flexing beyond its design limits, which points to delamination, broken structural supports underneath, or both. Random hairline cracks from age are normal. Patterned structural cracks are not.

🚩 Red Flag #5 — Electrical Work Done by Someone Who Has Never Been on a Boat

This is the most common and most dangerous problem I find in yacht surveys, and in my experience it is also the most underestimated.

Marine electrical systems are not household electrical systems. The wire grades, connector types, terminal specifications, and safety requirements are entirely different. A boat's electrical environment involves vibration, salt air, humidity, and proximity to fuel — a combination that turns non-marine wiring into a fire risk over time.

Look behind every panel you can access. What you are looking for: household cable (the round, grey, twin-and-earth wire you find in walls) used inside a boat, bare wire ends joined with standard wire nuts instead of marine crimp terminals, wiring that has been extended with a different gauge of cable and taped together, any cable running within 30cm of a fuel line or fuel tank without insulation.

In one boat I surveyed, I found the bilge pump wiring had been repaired with household cable and the connection was taped with electrical tape that had already started to tear off in the bilge humidity. That pump would have failed precisely when it was most needed.

A boat where the electrical system shows signs of non-marine intervention requires a full rewiring assessment by a qualified marine electrician before purchase. Budget accordingly — or walk away.