Recently we have developed a very interesting solution to the design of a swing keel. We have worked closely with manufacturers who have more than 20 years experience with swing keels in one-off boats of up to 80 feet. More than 40 of these one-offs are sailing, mostly in the North Sea and to distant shores, often very successfully as racing boats as well. We have distilled all the experience of these customers and constructors, and have developed a very clever design.
Our system operates with an electro-hydraulic powered swing keel that carries the whole weight of the ballast in the swinging part. It protrudes about 15cm out of the hull and distributes the weight of the boat on a very long support together with a small grounding plate around the lifting keel box. We use a double rudder system. On grounding, the depth of the rudders is only 5 cm less than the hull, and the rudders are very strongly built so that the boat is supported not only by the flat hull but also by the double rudders.
When sailing, our system ensures a perfect performance with a very deep centre of gravity, especially when compared to all the other systems on the market which carry most of the weight in the grounding plate and therefore need nearly double the weight of ballast without ever reaching the same stability.