Catana Catamarans

The Hulls

The elongated, torpedo-shaped hulls lessen the "rocking chair" effect in heavy seas. (Fig.9) Section (A-A) of the CATANA hull creates less drag than a normal wide-hulled catamaran. Boat speed is therefore higher for the same sail area or equivalent engine power.  
The aerodynamic shape of the coach-roof (F) reduces windage, as well as being more aesthetically pleasing.  
When lifting the daggerboards, there is no drag when reaching or running, the boat cuts effortlessly through the water and cruising speed is much higher during long passages downwind (Fig.10). The volumes (C) at both ends of a CATANA floater are important, thus more resistant to pitching in the swell.

The daggerboards

As in the wings of certain airplanes, the daggerboards of a CATANA are geometrically changeable. When the wind strengthens, the helmsman slowly lifts the daggerboards as their pressure on the water increases with the square speed of the boat.  
This increases speed by reducing wetted surface and drag underwater, and allows a higher course, thanks to efficient laminar flow.  
The sabre-shaped daggerboards are laminated with uni-directional reinforcements. The daggerboard casings are totally waterproof and joined to the hulls in such a way that they have been deemed indestructible.  
They are carefully fixed to the hulls (Fig.11) by ribs (A) and braces (B) whereby the strain is taken along the whole length of the planking and at the bottom of the hull. Finally, a gusset brace aft (C), reinforced by lamination on the bottom of the hull, guarantees that any violent impact will damage the daggerboard itself but leave its casing and the bottom of the hull intact.