Polynesian Concept
Catamaran, twin daggerboards · Masthead Sloop · 1970–1972
A Rudy Choy-designed catamaran featuring a high sail-area-to-displacement ratio for spirited performance
Designed by Csk & Rudy Choy, built by W. D. Schock Corp.
- LOA
- Beam
- Displacement
- Hull type
- Catamaran Twin Dbrd.
Is it for you?
Character
Where this design lands on the numbers a shopper trusts — read straight from her own ratios.
Shoal draughtDraws 0.48 m, board up where she has one — creeks, sandbars and thin anchorages most keels have to stay out of.
LightD/L 87Heavy
EasygoingSA/D 41.5Powered-up
- Lighter than ~87% of boats her size on file
- Narrower than ~83% of boats her size on file
Compared with 215 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
Masthead Sloop
Ratios
SA / displacement
41.5
Displacement / length
86.5
Hull
Hull type
Catamaran Twin Dbrd.
Construction
Fiberglass
Production
Years built
1970–1972
Units built
12
Designer
CSK, Rudy Choy
Builder
W. D. Schock Corp, CSK, Schock W.D
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.
Gemini 105MC10.21 mSame hull family1.1 m shorterA versatile cruising catamaran featuring a cockpit that converts with canvas or solid panels for all-weather comfort
Gemini Legacy 3510.77 mSame hull family0.5 m shorterA high-performance fractional catamaran featuring a Warren Luhrs-designed cockpit and shallow 0.86m draught
Dragonfly 4012.40 mSame hull family1.1 m longerA high-performance swing-wing trimaran featuring carbon-fiber construction and a high sail-area-to-displacement ratio
Astrea 4212.58 mSame hull family1.3 m longerA Berret-Racoupeau designed catamaran with a shallow 1.25m draft, built for stable cruising between 2018 and 2025
Fp 4112.10 mSame hull family0.8 m longerA 2025 catamaran successor to the Astrea 42, featuring a 1.35m draft and the choice of diesel or electric propulsion
The family
Boats like this
Nearby designs by size, type, and era — worth a look alongside her.
Schock 41A William E. Cook-designed masthead sloop with a high sail-area-to-displacement ratio built for performanceSchock 25A lightweight fractional sloop designed by Seymour Paul with a high sail area-to-displacement ratio for spirited racingAloha 30A Ron Holland-designed fractional sloop with a high sail-area-to-displacement ratio, built for performance-minded cruising
Keep looking
Nothing filmed of this one yet
Two ways to keep looking — both search what the fleet has actually recorded.
The newsletter
New boats, new stories. Every week, everywhere.
One email from the fleet — boats newly added, videos newly analysed. No noise.