The modern hulls are more and more balanced in heeling. They are
too more and more wide in the stern what allows to put them out of the true.
It leads quite naturally to the bi -
Better control as reaching as tacking
Is positioned every rudder around one
heeling average from 13 to 15 ¨ in the middle of the streamlines. In these
conditions, the rudder to leeward is perfectly fed in the middle of the drainage. It
becomes vertical, its shovel is always immersed, there is so less ventilation and
unhooking of the profile.
As a consequence, well positioned in the
drainage, its efficiency and its preciseness increase so that its size can be
decreased while keeping the control of the boat much more late. Reaching in great
speed, this greater directional control allows to navigate much more quietly in more
With two smaller rudders, the
efforts decrease much and the safety increases.
The rudders are much smaller and
briefer so double less loaded in equal control. The effort is less important on the rudder
stocks, the moment of the flexion which determines the resistance of the rudder stock is
the product of the distance of the stress and of this stress (determined by the surface
and the speed): distance and surface decrease.
Bi - rudders, additionally, free the
centre of the transom in the case of retractable rudders on the transom and allow to
facilitate the access of it: boarding, bathing, fishing, even for outboard engine
depending on the cases.
From the mini - transat to the 60 feet,
our racing boats which are equipped with it won everything. Bi - rudders make them even
easier to lead solo; and what is more comparable with a cruising boat than the boats
the only rating rule of which are: one man, the wind, the sea.