Catamaran, twin centreboards · Frac. Sloop (Rotating Spar) · First built 1964
A lightweight catamaran with a rotating spar, developed from the Thai Mk IV as a smaller sibling to the Shark 20
Designed by Gibbs, MacAlpine-Downie & Dick Gibbs.
LOA
Beam
Draft (max)
Displacement
Hull type
Catamaran Twin Cbrd.
Is it for you?
Character
Where this design lands on the numbers a shopper trusts — read straight from her own ratios.
TrailerableBeam 2.41 m — inside the 2.55 m no-permit tow width across most of Europe, and the 2.59 m US and Canadian limit. About 113 kg of hull, so roughly 700 kg on a trailer: check that against your own towing rating.Ramp-launchableAbout 113 kg of hull, with a keel that raises or a draft shallow enough to float off a trailer — she can go back on the trailer at the ramp, not only into the water.Shoal draftDraws 0.09 m, board up where she has one — creeks, sandbars and thin anchorages most keels have to stay out of.
LightHeavy
27 — light for her waterline, so she is easily driven and quick to accelerate.
Displacement / length 27
EasygoingPowered-up
94.8 — a lot of sail for her weight; powered-up and eager, a real performer.
Sail area / displacement 94.8
Lighter than ~78% of boats her size on file
Compared with 147 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
Frac. Sloop (Rotating Spar)
Ratios
SA / displacement
94.8
Displacement / length
27.3
Hull
Hull type
Catamaran Twin Cbrd.
Construction
Wood
Production
Years built
First built 1964
Designer
Gibbs, MacAlpine-Downie, Dick Gibbs
Builder
Gibbs Boat Co, MFG Boat Co (USA
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.
Supercat 154.65 mSame hull family0.8 m shorterA high-performance beach catamaran with a rotating spar and an exceptional sail-area-to-displacement ratio
Hobie 165.05 mSame hull family0.4 m shorterThe most popular sailing catamaran ever built, featuring a rotating spar and boardless hull for high-speed beach sailing
Hobie Tiger 185.51 mSame hull familyNear-identical lengthDesigned to the Formula 18 rule, this 5.5-meter catamaran features twin daggerboards and a high power-to-weight ratio
Hobie FX One5.18 mSame hull family0.3 m shorterA 5.18-meter single-handed catamaran featuring a rotating fractional rig and an exceptional 56.56 sail area-to-displacement ratio
Hobie 21 SE6.48 mSame hull family1.0 m longerA high-performance catamaran with a rotating spar, originally developed as a one-design for professional racing
Astus Boats 226.65 mSame hull family1.2 m longerA Stephan Vallet-designed trimaran with a high sail-area-to-displacement ratio built for rapid, stable coastal cruising
