Design and Construction
Where the IOR rulebook of the late seventies rewarded miniature transoms and bulged midsections, the Duetta 86 went the other way: an elongated hull with an astonishingly wide stern that stays good-natured even when heeled anchor. The Van de Stadt hand is evident in that refusal to chase the prevailing fashion. Below the waterline the boat draws either 1.10 m or, as an alternative, 1.50 m, and the 1.3-tonne iron ballast represents 43 percent of the 3.0-tonne displacement — a proportion that explains the steady, reassuring motion owners value in a cruising design.
Construction paired a solid-fibreglass hull with a balsa-cored deck, the core omitted only in critical structural zones where full laminate was retained. The deck and hull were joined in the monocoque manner Dehler used in that era, laminated together inside the mould for a continuous bond. Jetties are supported below deck on flat steel tied into the hull, so rig loads find a direct path and local moisture in the lockers is not an immediate threat to the mast step.
Rig and Handling
The Duetta 86 is a masthead sloop with a variable sail plan built around a 12-metre mast and a 441-square-foot total area, the 150-percent furling genoa alone accounting for 22 square metres. A strong sweep to the spreaders keeps the main from being eased very far off when reaching, a limitation noted by period testers but one that suits a boat pitched at steady cruising rather than all-out downwind running. The standard arrangement is a tiller, though some were finished with a wheel; the "A" version specifically carries a steering column with hydraulic control to the quadrant, which writing in YACHT test sailors found robbed the helm of feedback and made the boat feel less agile anchor. The mainsheet on that version is fixed to the floor ahead of the column and is not easily reached from the seated helm, a quirk of the layout rather than a defect. A self-tacking jib was offered as an alternative, and in light gusts the hull will quietly make a little more than five knots.
Accommodations
Three interior versions were catalogued. The "L" places a double berth under the foredeck, followed by a saloon with an L-shaped galley and a cockpit that runs right to the transom. The "G" drops the forward berth in favour of interior lockers and a large sail locker reached from the deck, with two dog bunks instead. The "A" — the layout YACHT surveyed — trades the foredeck berths for a separate aft cabin and two single berths, its cockpit sliding forward to open the space. In the "A" and "G" the saloon table drops to form a sunbathing platform 2.06 m long, 2.03 m wide aft and 1.48 m wide forward, with the mast support standing at its centre. Berths throughout are sufficiently large, storage is plentiful, and the four-person saloon seat around a rotating table is genuinely sociable. The galley doubles as a semi-cardanic navigation table under a hinged shelf. The WC room is very small — the door must stay open to dress.
Known Issues
Moisture is the recurring enemy. Hairline gelcoat cracks let water into the laminate around the starboard dunnage on the test boat, and the same mechanism threatens the mast base, where a wooden core was damaged by leaking electrical plugs, 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. Cockpit bilge hoses hang on copper standpipes that rise above the waterline but carry no sea valves, and the durability of their hull connection is questionable. There are no seacocks on the cockpit drains. Hatch seals and windows wear with age, though replacement rubbers are obtainable. Rudder bearings wear, evidenced by the blade slapping under power. Old single-circuit-cooled engines have often expired. The gelcoat chalks and must be repainted; the Treadmaster deck covering is labour-intensive to renew; and the many ABS moulded parts — inner shell, washbasin, hatch garage — are irreplaceable and must be rebuilt in GRP if broken.
Refits and Ownership
The "S" suffix denoted more luxurious fit-out: teak rubbing strake, teak in the cockpit, Treadmaster, and a gas cooker. When that teak rubbing strake wears, plastic replacement is now the pragmatic choice. The original gas cooker has no modern substitute, so owners improvise. The marina team at Großenbrode keeps a stock of many Duetta spares, a useful resource given how many small fittings have passed out of production. Engines seen include the robust Yanmar 2GM20 described in the survey and, as an alternative, Farymann diesels.
The Verdict
The Duetta 86 is a thoughtfully unconventional small cruiser from the Van de Stadt years at Dehler — wide-sterned, well-ballasted, and genuinely family-friendly in its several layouts. It rewards careful moisture management and forgives a lot through its redundant structure, but the discontinued ABS interior parts and absent seacocks demand a buyer's eyes open.
Pros
- Elongated, wide-aft hull with 43% ballast ratio and good-natured heel behaviour
- Three distinct interior versions suiting different cruising needs
- Monocoque hull-deck bond and steel-supported jetties protect rig integrity
- CE category A rating on a theoretically trailerable 28-footer
Cons
- Hydraulic wheel helm gives no feedback and mainsheet is awkwardly placed
- No seacocks on cockpit drains; questionable copper standpipe hull joints
- ABS interior parts irreplaceable; gelcoat chalks; balsa deck core moisture-sensitive
- Original gas cooker and many fittings out of production
