Rudder Adjustment

Gudgeon adjustment for compatibility with boat transom/stern

   Rudder for catamaran & sailboats

Sailors can adjust the distance between the upper and lower gudgeon, thereby enabling compatibility with diverse boat transoms/sterns. The upper gudgeon slides freely along the rudder box track. Position it according to your boat's specific transom/stern dimensions and fix it in the track by screwing in the four screws supplied.

Variants of a rudder setting with holes in the gudgeons.

Variants of a rudder setting with pins in the gudgeons.

When installing, make sure the upper gudgeon swivels freely when the rudder is turned

The track of the rudder box should not be obstructed by any transom/stern fitting when the rudder is turned one way or the other.

The lower gudgeon can encounter boat transom/stern fitting/s when the rudder is turned one way or the other, without any problem.

Blade Angle Adjustment
The angle of the blade can be adjusted fore and aft by lengthening or shortening the coulisse connector. To rake the blade to fore, simply rotate the coulisse connector in an anti-clockwise direction. To rake the blade to aft, simply rotate the coulisse connector in a clockwise direction. Screwing the coulisse connector one turn anti-clockwise will rake the blade to fore by β=2.1°. If the connector is rotated 8 times, the blade is raked to fore by a maximum β=16.8 °.

Adjusting the Pressure under which the Rudder Kicks Up
You can easily adjust the rudder to kick up at various pressures with a 3-position rubber stopper (located on the inside of the rudder box).

Adjusting the Pressure under which the Rudder Kicks Up

To open the rudder box in order to adjust the rubber stopper, disconnect the coulisse connector from the blade by undoing the nut and removing the bolt.
Lift up the tiller housing.

Unscrew the bolt on the Lock.
Insert the rubber stopper into the position you require (see a, b, c below).
Reassemble the system (reconnect the blade to the coulisse connector and close the tiller housing).
Check to verify that the pressure required to kick up the rudder matches your requirement.

Three rubber stopper positions for 3 levels of pressure under which the rudder kicks up.

Rubber stopper in uppermost position - highest pressure will be required for the rudder to kick up. Rubber stopper in middle position - average pressure will be required for the rudder to kick up. Rubber stopper in lowermost position - the least amount of pressure required for the rudder to kick up.

Disabling the Kick-Up Feature, Fixing the Blade in its Vertical Position

The Dotan's kick-up feature can be disabled by an optional lock-pin feature. The lock-pin can optionally be inserted into the rudder box's lock hole, fixing the blade in an up or down position, thereby disabling all kick-up/lowering capability.

If you use this feature, don't forget to remove the pin before putting to shore!

You can use this feature when:

  • You need to comply with Optimist class rules.
  • You need a safety catch when sailing in deep water to prevent the blade from being kicked up by accident.
  • You're sailing in jellyfish conditions.
  • You're sailing in storm conditions.
  • You're an inexperienced "first time" sailor.
  • You're transporting your boat on a trailer/dolly in an up position (you don't need a rope).


Dotan`s rudder benefits

  • Flick-of-the-Wrist Magic

    Dotan's conceptually brilliant rudder mechanism enables you to set the blade with a simple flick of the wrist. This action takes less than a second
    Say goodbye once and for all to ropes, elastic bands, fly-nut, screw-in rudder systems and multi-step setting and lifting actions.
  • Rudder Box: Constructed of Non-Corrosive

    Incomparably strong and matchlessly durable, using non-corrosive, composite materials which make the Dotan rudder box more steadier against dynamic loadings than aluminum boxes.
  • Rudder Blade 

    The rudder blade is lightweight and yet durable thanks to the integrated spar and special know-how of high-pressure technology with thermal shock.
    The Dotan rudder blade's profile is designed on the basis of the STEINER and NACA 0009 hydrodynamic profile (National Advisory Committee for Aeronautics). The Dotan rudder blade's shape minimizes wave and inductive resistance (more info.)

  • Rudder Adjustment

    The design makes it easy to adapt the rudder box to a variety of sailing boats and catamarans. The rudder box provides the ability to adjust the distance between the gudgeons.
  • Encountering obstacles

    When hitting underwater obstacles such as rocks, sandbanks, jellyfish, etc., the blade automatically kicks up.


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