An Automatic Daggerboard click here to read or make an observation about this  article
By Bernd Kohler - The Netherlands

Revering to Mr Szudy`s article about dagger boards. They can be a necessary nuisance. But are also helpful sailing to windward. As you will know I am a multihull person. Good ability to sail to windwards is for this type of boats even more important. Because fast multihulls sail for about 60% of the time to windwards (apparent wind). I found for some hull cross section, with my anti-vortex panels, a simple solution.

A-symmetrical hulls need no boards at all. My catamaran designs up to 9m (27ft) have daggerboard rudders with an automatic kick up system. When an obstacle is hit (also logs), the rudder is pulled out of the slot and the bungee cord pulls the rudder up. To get the rudder down again you push the rudder down till it jumps in the slot again.
We have used this rudder system now for 22 years without problems on different multi hulls.

Dagger board rudder on a DUO 425 beach catamaran.
Rudder in up position.

The system can be also adapted for daggerboards. (See sketch below - This is a dimensionless drawing to explain the function.) The dagger board case has to be angled on the front, so that the dagger board can slip out of the key. So when an obstacle is hit the PVC tube will be bent and the dagger board turns forward. At this moment the slot in the board falls out of the key and the bungee cord pulls the board up.

To have the board working again push it down till the key falls in the slot again. The bungee cord is fastened to the dagger board case with clamps. The PVC tube (for small boats a tube like that used for electric wiring will suffice) is very important. The tube holds the board back in the dagger board case and in this way the board in the slot under normal sailing conditions.

The length and diameter of the bungee cord has to be found out for every boat. If the dagger board case is short the leverage of the cord can be improved by leading the cord backwards. Use sheaves on each side in this case.

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