Both Andre Hoek and Holland Jachtbouw have in the past worked on yacht designs that incorporated lifting keels, so they were familiar with the advantages and disadvantages of such technology. Skylge is the largest collaboration between the two parties and thus presented significant challenges. The downside to a lifting keel is that the forces created while under way literally work to pry apart the gap in the hull’s bottom. Skylge’s lifting keel covers a range between 3.2 and 5.2 meters and is fitted with a 35-ton lead bulb on the bottom that creates a substantial righting moment. This exacerbates the well-documented "wedge effect," which happens when one side is pushed outboard and the other is forced inboard. (Click image to enlarge)

To solve the problem, Frans Brandjes Engineering, Hoek Design and Holland Jachtbouw closed the circuit between the hull and keel using large-diameter pins that harness the forces acting on the hull frame, fore and aft and side to side. The pins connect the lifting keel to the hull’s bottom plating through holes in the plating. An elastic rubber lining makes for a rattle-free connection (and can also absorb shock loads in the event of grounding). (Click image to enlarge)

Hoek is convinced that the mechanism represents a technical breakthrough: "It’s a very smart design and, structurally, I think it is the best lifting keel ever built on a large yacht." (Click image to enlarge)