Roughly a thousand Duetta 86s were completed. The design carried a CE category A rating, marking it as a vessel intended for extended offshore passages rather than sheltered-water daysailing.
Design and Construction
The IOR rule of the late 1970s rewarded small transoms and bulging midsections, but the Duetta 86 took a different course. Its elongated hull has an astonishingly wide stern and remains good-natured when heeled. The Van de Stadt influence is clear in the design’s refusal to follow the prevailing fashion.
Below the waterline, the boat draws either 1.10 m or, as an alternative, 1.50 m. Its 1.3-tonne iron ballast accounts for 43 percent of the 3.0-tonne displacement, a proportion that helps explain the steady, reassuring motion owners value in a cruising design.
Construction combines a solid-fibreglass hull with a balsa-cored deck. The core was omitted only in critical structural areas, where full laminate was retained. Dehler joined the hull and deck in the monocoque manner it used at the time, laminating them together inside the mould to form a continuous bond.
Jetties are supported below deck by flat steel tied into the hull. This gives rig loads a direct path and means local moisture in the lockers isn’t an immediate threat to the mast step.
Rig, Steering, and Handling
The Duetta 86 is a masthead sloop with a variable sail plan built around a 12-metre mast and 441 square feet of total sail area. The 150-percent furling genoa alone accounts for 22 square metres.
The spreaders are strongly swept, which prevents the mainsail from being eased very far when reaching. Period testers noted this limitation, though it suits a boat intended for steady cruising rather than all-out downwind sailing. A self-tacking jib was also offered, and in light gusts the hull will quietly make a little more than five knots.
A tiller was standard, though some boats were fitted with wheel steering. The “A” version specifically has a steering column with hydraulic control to the quadrant. YACHT’s test sailors found that this arrangement robbed the helm of feedback and made the boat feel less agile. On that version, the mainsheet is fixed to the cockpit floor ahead of the column and isn’t easily reached from the seated helm. That is a quirk of the layout rather than a defect.
Accommodation and Layouts
Dehler catalogued three interior versions: “L,” “G,” and “A.”
The “L” has a double berth beneath the foredeck, followed by a saloon with an L-shaped galley. Its cockpit runs all the way to the transom.
The “G” omits the forward berth in favour of interior lockers and a large sail locker reached from the deck. It has two dog bunks instead.
The “A,” which was the layout surveyed by YACHT, trades the foredeck berths for a separate aft cabin and two single berths. Its cockpit is moved forward to create the necessary space.
In the “A” and “G,” the saloon table lowers to form a sunbathing platform measuring 2.06 m long, 2.03 m wide aft, and 1.48 m wide forward. The mast support stands in the middle. Berths throughout are sufficiently large, storage is plentiful, and the four-person saloon seating around a rotating table is genuinely sociable.
The galley also serves as a semi-cardanic navigation table beneath a hinged shelf. The WC compartment is very small: the door must remain open while dressing.
Known Issues
Moisture is the Duetta 86’s recurring enemy. On the test boat, hairline gelcoat cracks allowed water into the laminate around the starboard dunnage. The same mechanism threatens the mast base, where leaking electrical plugs damaged a wooden core, and the ends of the self-tacking rail, where expanding wood destroyed the surrounding laminate. The balsa deck core must on no account have been allowed to get damp.
The cockpit bilge hoses hang from copper standpipes that rise above the waterline but have no sea valves. The durability of their connection to the hull is questionable, and there are no seacocks on the cockpit drains.
Hatch seals and windows wear with age, although replacement rubbers remain obtainable. Rudder bearings also wear, as shown by the blade slapping under power. Old single-circuit-cooled engines have often expired.
Cosmetic and interior repairs bring their own complications. The gelcoat chalks and must be repainted, while the Treadmaster deck covering is labour-intensive to renew. Many fittings were moulded in ABS, including the inner shell, washbasin, and hatch garage. These parts are irreplaceable and must be rebuilt in GRP if they break.
Equipment, Refits, and Parts
The “S” suffix identified a more luxurious fit-out, including a teak rubbing strake, teak in the cockpit, Treadmaster, and a gas cooker. When the teak rubbing strake wears out, plastic replacement is now the pragmatic choice.
There is no modern substitute for the original gas cooker, so owners improvise. Many other small fittings have also gone out of production, although the marina team at Großenbrode keeps a stock of numerous Duetta spares.
Engines seen in the Duetta 86 include the robust Yanmar 2GM20 described in the survey and, as an alternative, Farymann diesels.
Verdict
The Duetta 86 is a thoughtfully unconventional small cruiser from Dehler’s Van de Stadt years. It combines a wide stern and substantial ballast with three genuinely family-friendly layouts. Its theoretically trailerable 28-foot hull also carries a CE category A rating.
The boat rewards careful moisture management and forgives a good deal through its redundant structure. Even so, absent seacocks, discontinued ABS interior parts, and other obsolete fittings mean buyers need to approach one with their eyes open.
Pros
- Elongated, wide-aft hull with a 43 percent ballast ratio and good-natured behaviour when heeled
- Three distinct interior versions for different cruising needs
- Monocoque hull-to-deck bond and steel-supported jetties that protect rig integrity
- CE category A rating on a theoretically trailerable 28-footer
Cons
- Hydraulic wheel steering gives no feedback, and the mainsheet is awkwardly positioned
- No seacocks on the cockpit drains, with questionable copper-standpipe hull connections
- Irreplaceable ABS interior parts, chalking gelcoat, and a moisture-sensitive balsa deck core
- Original gas cooker and many other fittings are out of production
