Keel design for shallow water

Philippe Briand P2 sailing yacht aerial racing — The Philippe Briand-designed yacht P2 as seen racing during the Loro Piana Superyacht Regatta

In the case of Vertigo, the 67.2m Philippe Briand ketch built by Alloy Yachts, the design team investigated the possibility of a lifting keel but in the end decided on a simpler solution a 5.1 metre draught fixed keel with a carbon composite daggerboard that can be lowered through the bottom of the keel to increase draught to 9.1 metres.

When we started looking at the possibility of a lifting keel, recalls Briand, we found ourselves venturing into an unexplored area. Today I believe Kokomo, at 59m, has the largest lifting keel ever. But it is very uncommon at this size. After discussions with the owner and everyone involved, we decided not to go for so much complexity.

Akalam, a 32m yacht designed by Íñigo Toledo of Barracuda Yacht Design, is similar to Vertigo: she has a fixed 3.6 metre draught keel with a daggerboard that takes the draught to 5.5 metres.

The possibility of canting keels

But what of the canting keel? Its had a chequered history in the world of grand prix racing such as the Volvo Ocean Race and the Vendée Globe where we have seen numerous breakdowns of canting keel technology. The number of life-threatening incidents should be enough to put any safety conscious cruising sailor off the idea.

Jim Pugh, however, says it would be unfair to dismiss the concept entirely. With Reichel/Pugh having designed the likes of Alfa Romeo and Wild Oats

Theyre certainly worth looking at for the massive gain in stability you can achieve, says Pugh, although he admits they are expensive and high maintenance, and require a constant and reliable power source (and back-ups) such as a running engine available to power the keel from side to side.

Like Reichel/Pugh, Finot Conq is a design office perhaps best known for its work in the grand prix race world, but which now finds itself in increasing demand from ambitious superyacht owners looking for high-performance cruising yachts. The French design house beat off strong competition for the right to design a new 30m yacht with the simplest yet most ambitious of briefs from the client: to design the worlds fastest 100-foot cruising yacht.