At 18ft long with a total allowed rig area of 150ft2, but weighing in at a mere 75kg, the ‘A’ Class is very much a Formula One car in catamaran form and in the last few years, developments have seen this class take off more than ever before, quite literally.

Open Waters waters has taken this box rule class and added some unique concepts. The boat is designed and built in Canada. Naval Architect Simon Rees designed the Hull form and Professional engineer Simon Angus designed the composite layups, mast, deck, rigging and foil controls. The main foils used on the boat are designed by world renowned Spanish designer Gonzalo Redondo from 3D applied technologies. 

The most unique design feature of this boat is the solid deck. The deck offers 3 significant advantages;

1. The solid deck means the air pressure between the water and deck is more consistent allowing for a greater ground effect to be created. This does not generate lift as typical wings, however the increase in pressure below the deck pushes up on the boat allowing it to foil in lighter conditions. 

2. Stiffness. Having a larger connection to each hull and a 2.5" gap between the deck makes the boat incredibly stiff

3. The deck sweeper sailing has a sealing surface on the upper deck. This significantly increased the efficiency of the lower part of the sail which is exactly where it is needed. 

Probably the biggest difference with our design is Price. We sell our boats for $30,000 CAD. Which is only $23,000 USD at time of writing. This makes it one of the most affordable carbon fiber catamarans on the market. 


The boats is manufactured from one of the best materials available.

Carbon fiber - Vector ply supplies a unique layup of unidirectional and double bias fiber which allows for the fabrics to be placed in the orientation where the strength is required.

Resin - Proset Infusion Epoxy is used on all our parts. The ultra low viscosity resin is infused under vacuum into each part and post cured at elevated temperatures to give physical properties of nearly twice that of polyester resins. 

Core material. The core material used is Gurit M80. It is a marine grade structural foam with a density of of 85 kg/m³. It features high shear strength with low density, high temperature processing and high elongation for toughness. 

Adhesive. Plexus MA310 is the adhesive of choice for the build. The very high shear strength of the product (over 3000 PSI) allows for both flat and fillet adhesive construction.


The hulls are molded in 2 pieces and attached together with  adhesive. There are 5 bulkheads in each hull which add rigidity and strength. The Carbon-foam sandwich construction provide a light weight stiff hull.


The decks are a similar fiber schedule as the hulls with additional reinforcement where required by design. The solid deck is a unique feature of our boat. The solid deck promotes the ground effect  phenomenon help to get the boat out of the water sooner.


The mast is design and manufactured by Open Waters. Base load deflection calculations where obtained from the sail manufacture and a carbon layup schedule was Engineered to develop the required bend. The standing rigging is all 4mm Dyneema from Marlow Ropes.  The Angle of the spreader and tension on the diamonds is adjusted by turn buckles. The Mast mast is carbon fiber plate with a brass ball and socket fitting to allow for full rotation of the mast at the  rake angle of 5 degree's. The hound and the diamond connections are made form carbon plate and adhered with a Plexus adhesive to reduce weight and evenly distribute the loads. 


The running rigging is all Marlow ropes and Ronstan blocks and cams. The rigging is designed for a 10:1 mainsheet and 12:1 Cunningham with 2:1 systems on the mast rotation, foil angle and traveler. All of the rigging is hidden under the deck to allow for a sleek aerodynamic design.



The rudders are carbon fiber with a custom aluminum housing. The angle trim of the rudders is simply controlled by a wing nut.  The rudders are an Open Waters Design & Manufacturing


The shape of the foils are designed by world renowned designer Gonzalo Redondo from D3 Applied Technologies and manufactured by Open Waters Design and Manufacturing. The foils are fully retractable from the deck of the boat in accordance with A class rules.

Last updated 4 June 2018