Dufour 31 Information, Review, Specs

Sailing Performance & Handling

The Dufour 31 is a quintessential cruiser of the "heavy-displacement" mindset, though by modern standards it is perhaps more accurately described as moderate-heavy. With a displacement of roughly 9,480 lbs and a fin keel of approximately 3,750 lbs, it carries a respectable ballast ratio of nearly 40%. This translates to a stiff, stable platform that stands up well to its canvas in a blow. According to archival technical reviews from the period, the 31 was praised for its "sea-kindliness," a term referring to its smooth motion in a seaway compared to the more nervous, modern light-displacement hulls.

Its underwater profile features a high-aspect fin keel and a skeg-hung rudder, a combination that provides a balanced feel on the helm. While it lacks the ultimate light-air agility of a racing boat, the 31 tracks exceptionally well, reducing the strain on the helmsman during long passages. Owners often report that the boat finds its "groove" at about 15 knots of apparent wind, at which point the hull’s generous beam provides significant secondary stability. Because it utilizes a masthead sloop rig, the primary power comes from the headsail; modern owners often find that upgrading to a high-quality furling genoa significantly improves its performance in varied conditions.

Interior Comfort & Variations

The hallmark of the Dufour 31 is its "big boat" feel, achieved through a beam of 10 feet 6 inches—an expansive measurement for a 31-footer in the early 1970s. This width allowed Michel Dufour to design an interior that felt less like a tunnel and more like a living room. The layout typically features a classic V-berth forward, followed by a full-width head compartment that separates the sleeping quarters from the main salon.

In the salon, the 31 offers a high level of joinery for a production boat of its age, typically finished in rich African mahogany. The L-shaped galley is situated to port, while a dedicated, forward-facing navigation station sits to starboard—a luxury often sacrificed in modern boats of this size. Headroom is a notable highlight, standing at approximately 6 feet 1 inch, which accommodated taller sailors in a way few of its contemporaries could. While no major structural hull variations were produced, later models often featured updated interior upholstery and minor cabinetry refinements. The Dufour 31’s siblings include the smaller Dufour 29 and the larger Dufour 35, both of which share the same aesthetic DNA and robust construction standards.

Known Issues & Buyer’s Checklist

Prospective buyers should approach a Dufour 31 with a focus on its 1970s-era mechanical and structural systems.

• Engine Obsolescence: Many original 31s were fitted with the Volvo Penta MD7A or MD7B. While reliable, these engines are now decades old, and sourcing specific replacement parts can be difficult. A repowered vessel with a modern Yanmar or Beta Marine engine carries a significant premium.
• Chainplate Leaks: Like many boats with deck-mounted chainplates, the 31 is prone to water ingress if the sealant has not been regularly maintained. Over time, this can lead to saturation of the bulkhead timber.
• Rudder Skeg Integrity: The skeg-hung rudder is a safety feature, but the connection point between the skeg and the hull should be inspected for stress cracks or signs of "play" in the bearings.
• Osmotic Blistering: Vessels from this era were built before the widespread use of vinylester resins. It is common to find minor osmotic blistering in the gelcoat; while rarely structural on a hull this thick, it is a factor in valuation and maintenance.
• Deck Core: The decks are balsa-cored. Use a moisture meter or perform a percussion test (tapping with a plastic hammer) around stanchion bases and cleats to check for delamination or soft spots caused by water intrusion.

Community & Resources

The Dufour 31 benefits from a robust network of European-based associations. The Dufour Association (UK) provides an extensive technical library and owner forums that cover many of the maintenance hurdles specific to 1970s models. In France, the brand’s heritage is closely guarded by several regional clubs that organize rallies and provide a repository for original boat manuals and wiring diagrams.

The Verdict

The Dufour 31 remains a premier choice for the budget-conscious sailor seeking a "real" offshore-capable cruiser under 35 feet. It lacks the flat-out speed of modern designs but compensates with a sense of security and a spacious, traditional interior.

Pros:

• Excellent stability and predictable handling in heavy weather.
• Impressive headroom and interior volume for its length.
• High-quality mahogany joinery that ages gracefully.
• Strong secondary market with an active community.

Cons:

• Original Volvo Penta engines may require replacement or specialized care.
• Slower in light air compared to modern fin-keel designs.
• Balsa-cored decks require vigilant monitoring for moisture.