weight penalty. Also, since hydrodynamic drag increases with weight, there is a straightforward quest to keep the displacement as light as practical while achieving an adequate carrying capacity and maximum stability. Any kilo of structure saved either reduces displacement or allows more weight in the keel, more stability, safety and comfort, and enhanced performance. Up to now these matters have been given little scientific study by the cruising yacht designer.

Although most of my work these days is designing large cruising yachts, I remain involved in the racing scene. There is an intellectual challenge about it, and undoubtedly the associated research and development has beneficial spin-offs for all my yacht design projects.

Recently my highest profile racing design project was collaborating on the New Zealand America's Cup Challenger KZ- Kiwi Magic. The keel