Yonne Class Information, Review, Specs

Sailing Performance & Handling

The Yonne Class is a pure performance machine that relies on a high power-to-weight ratio to achieve early planing. With a displacement of approximately 1,200 kg and a generous sail area, it exhibits the typical "Open" design characteristics popularized by the Finot-Conq office in their offshore racing designs. According to technical assessments by the designers, the boat was engineered to plane in as little as 12 knots of true wind speed, particularly when utilizing the large asymmetrical spinnaker flown from a retractable carbon bowsprit.

Handling is sharp and dinghy-like, thanks to a deep, high-aspect fin keel and a powerful spade rudder. The boat’s stability is derived primarily from its 2.50-meter beam, which provides significant form stability. Owners often report that the boat feels exceptionally "stiff" for its size, allowing for aggressive upwind work even in a chop. The ergonomics of the cockpit are optimized for a crew of three to four, with a layout that prioritizes quick sail adjustments. Unlike heavier cruisers of this length, the Yonne Class requires active weight management; however, its tracking is surprisingly stable due to the refined underwater hull shape.

Known Issues & Buyer’s Checklist

Prospective buyers should approach the Yonne Class with a "racing boat" mindset, focusing on structural integrity and rig tension rather than domestic amenities.

• Keel Trunk and Pivot: The lifting keel mechanism is a primary point of inspection. Check for excessive play in the trunk and signs of stress cracking around the pivot bolt. Water ingress or weeping at the keel box joint is a known signal of structural fatigue or hard groundings.
• Composite Delamination: Being a performance-oriented composite build, the deck and hull should be "tapped" or moisture-tested, especially around high-load areas like the chainplates and the mast step. Any soft spots in the sandwich core can compromise the rigidity required for the boat's high-tension rig.
• Rudder Bearings: Given the high speeds and loads this boat achieves, the rudder bearings often exhibit wear. Excessive vibration at the helm or a "clunking" sensation when transitioning through tacks indicates that the bushings require replacement.
• Rigging and Bowsprit: The carbon fiber bowsprit should be inspected for longitudinal cracks or UV damage. Additionally, because these boats are often campaigned heavily, the standing rigging should be meticulously checked for "fish hooks" or terminal corrosion, as the high-tension setup leaves little margin for error.

Community & Resources

The primary resource for technical data and design philosophy for the Yonne Class is the Finot-Conq Architectes technical archive. While a dedicated "Yonne" owners' association has largely merged into broader sportboat and "Class 7.50" racing circles, technical support can still be found through French racing forums and local sailing clubs in the Yonne and Brittany regions where these boats were most active. Technical drawings and original specifications are often maintained by the Finot-Conq design office for refit purposes.

The Verdict

The Yonne Class is a niche, high-performance day-racer that offers exhilarating speeds for sailors who prioritize technical handling over comfort.

Pros:

• Exceptional Speed: Capable of sustained planing and double-digit speeds downwind.
• Trailability: The lifting keel and 2.5m beam make it legal for road transport in most jurisdictions.
• High-End Pedigree: Designed by the same office responsible for world-beating IMOCA 60s.

Cons:

• Minimalist Design: Entirely lacks an interior, making it unsuitable for anything beyond day-sailing or "camping" style trips.
• High Maintenance: Requires a high level of maintenance for the standing rigging and lifting keel mechanism.
• Physicality: Demands an active, athletic crew to sail safely and effectively in heavy air.