In order to prevent the boat from slipping sideways in case of sidewinds and providing a center of rotation to improve maneuverability it was decided to add a small keel. This decision also adds a few other benefits:
Although the selfrighting ability of the hull doesn’t inevitably require a weighted keel, we will probably take the opportunity and add some weight at the bottom of the keel to lower the center of gravity.
The keel also helps damping rolling motion of the boat and most important enables us to create a balanced helm.
It is important for the boat to not turn away from the weather in sidewinds due to the drag of the propolsion unit in the stern area and the high profile of the bow part. That kind of behaviour would require a lot of thrust and steering movement to counteract wich would definitely cause trouble in high winds. Our very basic approach of finding the correct position of the keel simply involved shifting the longitudinal center of area (COA) of the wetted surface profile right below the longitudinal COA of the freeboards profile by changing the keels position and length. In the picture below you can see the profile of the final hull and the COA of both wetted surface and freeboard profile.