Hidden defects on a used boat: what French law says, how to protect yourself

Hidden defects are the nightmare of both sides of a used boat sale: the buyer fears discovering osmosis or a tired engine six months later; the seller fears being sued for a defect they knew nothing about. French law answers both, and it is more precise than people think. This guide gives the principles in plain language; it does not replace a lawyer in a dispute.

What the French Civil Code says

The warranty against hidden defects (garantie des vices cachés) is set out in articles 1641 to 1649 of the French Civil Code (text on Légifrance, the official French legal website). Article 1641 lays down the principle: the seller is liable “for hidden defects in the thing sold which make it unfit for the use for which it is intended, or which so reduce that use that the buyer would not have acquired it, or would only have paid a lower price for it, had they known of them”.

For a defect to be a hidden defect, four conditions must therefore be met:

• It existed before the sale, at least in embryo. An impeller that breaks a year later is not a hidden defect; an old structural crack, covered up with paint, may be.
• It was hidden: a reasonably attentive buyer could not see it during the viewing. Article 1642 excludes apparent defects “which the buyer could have seen for themselves”. Worn antifouling, or a portlight that leaks during the viewing, are not hidden.
• It is serious: it makes the boat unfit to sail, or reduces its use so much that the buyer would not have bought it, or not at that price.
• The buyer was unaware of it at the time of the sale.

What the buyer can claim

Article 1644 gives them the choice: return the boat and have the price refunded (the action rédhibitoire, or rescission), or keep the boat and obtain a price reduction (the action estimatoire). If the seller knew of the defect, they also owe damages (article 1645). If they were unaware of it in good faith, they owe only the refund of the price and the costs of the sale (article 1646).

Time limits

The buyer has two years from the discovery of the defect to take action (article 1648), not from the sale. The discovery is often dated by the survey report that reveals the extent of the defect. In 2023, the French Court of Cassation (the highest civil court) specified that this two-year period is a limitation period — it can be suspended, for example by a court-ordered survey — and that it sits within an absolute ceiling of twenty years from the sale (joint chamber, 21 July 2023). In practice: a seller is not released two years after the sale; they are released two years after the buyer discovered the defect.

The “sold as seen, without warranty” clause

Between two private individuals, a clause excluding the warranty against hidden defects is in principle valid (article 1643: the seller is liable for hidden defects “unless, in that case, they have stipulated that they will not be bound by any warranty”). That is why it appears in most bills of sale. But it has two limits that make it less protective than people think:

• It is set aside if the seller knew of the defect: bad faith voids the clause. A seller who received a quote for osmosis repairs and said nothing about it cannot shelter behind “sold as seen”.
• It has no effect for a professional seller (boatyard, broker selling in their own name, charter company selling off its fleet), who is presumed to know the defects of what they sell.

Typical cases on a boat

• Advanced osmosis under fresh antifouling: the textbook case, especially if the seller had had the hull tested.
• Structure: hull-to-keel joint damaged after an undeclared grounding, cracked floors, concealed deck delamination.
• Engine: cracked cylinder head, corroded block, hour meter replaced without saying so. Simple wear, on the other hand, is not a defect: a 3,000-hour engine is a 3,000-hour engine.
• Old water ingress, corroded through-hulls, rotten bulkheads behind redone linings.
• Papers: a boat that cannot be registered (inconsistent hull number, no CE conformity for an imported boat) may fall under legal grounds other than hidden defects, but the result is the same for the buyer: they cannot sail.

Protecting yourself as a seller

• Say what you know, in writing, in the listing and in the bill of sale: a declared defect is no longer hidden. That is the best protection, well before the exclusion clause.
• Keep a record of what you declared and what the buyer saw: photos from the viewing, survey report handed over, list of documents provided.
• Keep a proven maintenance history: it shows what was done, by whom and when — and that there was no concealed repair. The Hullteam sale file is frozen at a date and timestamped by a third party: it records what the seller knew and said at the time of the sale.
• Offer or accept a survey before the sale: what the surveyor saw or could have seen is no longer hidden.
• Sign a clear bill of sale (official template) that describes the boat, its equipment, its declared condition and the documents handed over.

Protecting yourself as a buyer

• View the boat methodically (the checklist before you sign) and do a sea trial: what you should have seen will not be a hidden defect.
• Have the boat surveyed, hauled out and with the hull tested, for any boat of a certain value. The report dates the discovery of the defects and sets the starting point of the time limit.
• Ask for the history and read the levels of proof line by line; ask why a period is empty.
• Ask your questions in writing (email, messaging) and keep the answers: “has the boat ever run aground?”, “has the hull been treated for osmosis?”. A false answer to a precise question establishes bad faith.
• If you discover a defect after the sale: have it recorded quickly by a surveyor, write to the seller by recorded delivery, and consult a lawyer before committing to any work that would destroy the evidence.

This page is general information on French law as at the date it was last updated; it does not constitute legal advice. For a dispute, a lawyer or a consumer association will tell you what applies to your situation.