Modern hulls are more balanced while heeling. They are also wider in the stern.
It leads quite naturally to the twin rudders.
Better control when reaching and 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 little ventilation, and unhooking of the profile.
As a consequence, well positioned in the drainage, its efficiency and its precision increase so that its size can be decreased while keeping the control of the boat much longer. Reaching in great speed, this greater directional control allows navigating much more efficiently in more difficult conditions.
Greater safety
With two smaller rudders, the efforts decrease greatly and the safety increases.
The rudders are much smaller and briefer, so they are 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.
Twin – rudders, additionally, free the centre of the transom in the case of retractable rudders on the transom and allow facilitating the access to it: boarding, bathing, fishing, even for an outboard engine, depending on the case.
From the mini – transat to the 60 feet, our racing boats, which are equipped with it, have 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 is: one man, the wind, the sea.
Pascal Conq
In the 1990s till around 2011, the smaller First Series and the Oceanis Series with the lifting keel option were designed with twin keels: The Oceanis models include the 311, 323, 331, 343, 361. Then Sense Series in 2011 were the first models designed with twin rudders as standard with the Sense 43, 46, 50, 51, 55 & 57. Followed by the Oceanis 35, 35.1, 38 & 38.1 in 2014. Now all modern Oceanis are designed with twin rudders from the Oceanis 30.1 to the Oceanis Yacht 60.
Resources:
Beneteau Sailboats – Parts & Service
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