Diam 3 Information, Review, Specs

Sailing Performance & Handling

Handling the Diam 3 is an exercise in high-speed precision, governed by an extraordinary sail area-to-displacement (SA/Disp) ratio that far exceeds typical performance dinghies. With a total upwind sail area of approximately 21 square meters (227 sq ft) against its featherweight hull, the boat is notoriously responsive to gust inputs and trim adjustments. The use of a fractional sloop rig ensures that the headsails remain manageable during tacks, a critical feature given the boat’s propensity to accelerate rapidly out of maneuvers.

According to technical specifications from SailWiki, the boat utilizes twin daggerboards rather than fixed keels, allowing for highly efficient upwind tracking and a significantly reduced draft (as little as 0.12 meters) for beaching or downwind runs. In heavy air, the Diam 3 requires active weight management; the wide 2.60-meter beam provides a stable platform for the crew to hike out, but the fine, wave-piercing hulls demand constant attention to longitudinal trim to prevent the leeward bow from "digging in" during high-speed reaching. Owner anecdotes from performance sailing circles suggest the boat feels more like an F18 catamaran than a standard daysailer, rewarding technical skill with double-digit speeds in moderate breezes.

Popular Mentions & Media

While the Diam 3 did not achieve the same global mainstream recognition as its successor, the Diam 24, it maintained a strong niche presence in the European sport-multihull circuit. The boat’s developer, Vianney Ancelin of ADH Inotec, used the technical lessons learned from the Diam 3 to refine the construction methods used in the Diam 24 One Design, which famously became the standard platform for the Tour de France à la Voile in 2015. The Diam 3 is often discussed in French nautical media as a "stepping stone" design that proved the viability of high-tech, carbon-reinforced production multihulls for the amateur racing market.

Known Issues & Buyer’s Checklist

Prospective buyers of a pre-owned Diam 3 should focus on the structural integrity of the high-stress areas typical of carbon-reinforced sandwiches.

• Daggerboard Trunks: Inspect the trunks for stress cracks or delamination, as these areas bear significant lateral loads when sailing upwind at high speeds.
• Trampoline Tension: The trampoline serves as a structural member of the platform; check the grommets and the lacing tracks on the hulls for wear or pull-out.
• Carbon Reinforcements: Since the boat was built during a transitional period for ADH Inotec’s production methods, verify that the carbon-reinforced sections of the mast step and beam attachments show no signs of spiderweb cracking.
• Rudder Bearings: The high speeds generated by the Diam 3 can lead to accelerated wear in the rudder gudgeons and pintles, resulting in "chatter" or lost steering feel.

Community & Resources

The primary point of contact for technical support remains the manufacturer, ADH Inotec, located in the heart of Brittany’s "Valley of Sailing." While a specific "Diam 3 Class Association" is no longer active, the boat is frequently supported by broader multihull organizations in France. Owners often find technical overlap with the Diam 24 community, as many of the rigging components and construction philosophies are shared across the two models.

The Verdict

The Diam 3 is a specialized racing tool that offers a purist multihull experience for sailors who prioritize speed over amenities.

Pros:

• Exceptional power-to-weight ratio leading to high-performance sailing.
• Advanced construction materials including carbon fiber reinforcements.
• Very shallow draft with daggerboards raised, ideal for beach launching.
• Design pedigree from Bernard Desjoyeaux and ADH Inotec.

Cons:

• Requires a high level of physical fitness and sailing skill to handle safely in a breeze.
• Extremely limited production run makes sourcing model-specific replacement parts difficult.
• Lacks the versatility of a cruising catamaran; strictly a daytime racing platform.