A fractional sloop centerboard dinghy adapted from the Cape Cod Knockabout, built for speed with a high sail area ratio
LOA
Beam
Draft (max)
Displacement
Hull type
Centerboard Dinghy
Is it for you?
Character
Where this design lands on the numbers a shopper trusts — read straight from her own ratios.
TrailerableBeam 1.80 m — inside the 2.55 m no-permit tow width across most of Europe, and the 2.59 m US and Canadian limit. About 204 kg of hull, so roughly 800 kg on a trailer: check that against your own towing rating.Ramp-launchableAbout 204 kg of hull, with a keel that raises or a draught shallow enough to float off a trailer — she can go back on the trailer at the ramp, not only into the water.Shoal draughtDraws 0.15 m, board up where she has one — creeks, sandbars and thin anchorages most keels have to stay out of.
LivelySea-kindly
Her light displacement on a beamy beam gives 4 — a quick, lively motion that feels every wave.
Comfort ratio 4
CoastalBluewater
At 3.09 she sits above the 2.0 line — beamy for her weight, and happiest coastal.
Capsize screening 3.09
LightHeavy
64 — light for her waterline, so she is easily driven and quick to accelerate.
Displacement / length 64
EasygoingPowered-up
34.1 — a lot of sail for her weight; powered-up and eager, a real performer.
Sail area / displacement 34.1
Light and lively — happiest day-sailing and coastal-hopping in settled weather.
Heavier than ~79% of boats her size on file
Compared with 361 boats of the same type within a quarter of her length.
The record
Full specifications
The complete reference set — tap any figure to switch between metric and imperial.
Dimensions
Weights
Rig & sail area
Rig
Fractional Sloop
Ratios
SA / displacement
34.1
Displacement / length
63.6
Comfort ratio
4.3
Capsize screening
3.09
Hull speed
5.1 kn
Pounds / inch immersion
310
Hull
Hull type
Centerboard Dinghy
Construction
Fiberglass
Production
Years built
1960–1968
Builder
O'Day Corp
Boats like this, on the water
Nobody has filmed this one — but these are close.
Comparable boats the fleet has on camera: same type, within a quarter of her length. Open the boat, or watch the video — a timestamp means she only appears in passing.
O'Day Daysailer5.11 mSame hull family0.3 m longerA 1956 centreboard dinghy with a high sail-area-to-displacement ratio that remains in production today
Finn (Monotype)4.50 mSame hull family0.3 m shorterA Richard Sarby-designed Olympic single-handed dinghy featuring an unstayed cat rig and a long history of competition
Small Craft Ltd. Wayfarer4.82 mSame hull familyNear-identical lengthAn Ian Proctor-designed centreboard dinghy with a high sail-to-displacement ratio, built since 1957 in wood and fibreglass
Aubin (Chantier Aubin) Snipe4.72 mSame hull familyNear-identical lengthA legendary William F. Crosby-designed fractional dinghy that remains one of the world's most active racing classes
LaserPerformance 49er4.88 mSame hull familyNear-identical lengthAn Olympic-class high-performance skiff featuring a massive sail-area-to-displacement ratio for elite racing
