Retractable Y-shaped foils, adjustable in three dimensions

Inspired by the appendages of the America's Cup foiling monohulls, these Y-shaped foils have a wingspan of over 5 metres. They are designed to generate powerful lift, increase power and offer a wide range of adjustments to optimise flight at every point of sail and in all conditions. Beyond their impressive size, these foils feature many unique innovations.

Revolutionary U-shaped rudders

These are probably the most visually striking innovations on the new Maxi Edmond de Rothschild. To fly high above rough seas while maintaining control, the team wanted very long rudders that would remain in contact with the water. The challenge is that longer rudders tend to flex under load, severely affecting steering and the efficiency of their lifting surfaces. A new geometry was needed to give these appendages maximum stiffness, resist cavitation and ultimately improve control of the boat and make better use of its power. The result is a set of U-shaped rudders over 4 metres long, a metre longer than those on Gitana 17. Their shape, reminiscent of a tripod or an inverted π, is only the visible part of what makes them so distinctive.

A daggerboard optimised to stabilise the boat and limit cavitation

With its wide span, the daggerboard resembles an aircraft tail assembly, with two adjustable flaps: one on the vertical section and the other on the horizontal section, the distinctive “manta-ray wing”. On Gitana 18, the innovation is to position this wing behind the vertical part of the appendage, rather than directly beneath it, to minimise flow disturbance and cavitation.

Rig: adjustable spreaders to control mainsail power while sailing

Gitana 18’s mast is 1.50 metres taller than its predecessor’s. The boom is also shorter, creating a more slender sail plan. The major innovation is a set of spreaders that can be adjusted while sailing to bend the mast fore and aft. Actuated by hydraulic rams, these spreaders can pivot through 35 degrees to adjust the bend in the middle of the mast. This unprecedented system allows the sailor to control mainsail power: adding depth in light winds to take off sooner, or flattening the sail to reduce power at high speed or in strong winds. Adjusting the depth, and therefore the power, of the mainsail can also save a solo sailor time and energy by reducing the need for risky manoeuvres or headsail changes.

Central hull:
an integrated, structural coachroof

The naval architects and Gitana design team wanted an exceptionally stiff, structurally robust platform. This applies both to the floats, which must withstand heavy loads from the foils and rudders, and to the central hull, which is subject to torsion. The enclosed coachroof is integrated into the hull and contributes to its structural strength. Inside, the cockpit brings all sail-handling controls together, with ergonomics shaped by many hours of design and development. The coachroof also stands out for the number and size of its windows. This configuration meets the visibility requirements of the Ultim class rules and gives sailors the best possible view to keep a visual watch.

21.01.2008

Under a full moon.

par Gitana

We caught up with the trade winds during the wee hours of Sunday.

They are blowing at an obliging 30 knots on average, from 110°. With the staysail up and two reefs in the main, Gitana 13 is cruising along magnificently on an azure blue sea. They’re having a ball at the helm, despite taking spray as if from a fire hose. Result: 615 miles under our belt. This is to be expected: this wind angle and sail configuration always add up to excellent progress on the ocean.
Comfort onboard has obviously improved, apart from volleys of spray and big waves. We are in a real shaker, and the simplest act, like getting dressed, requires some technical prowess to avoid getting tossed from one side of the hull to the other. The same is true in the kitchen. The only culinary act possible is to heat water, which is just fine since that’s all we need to do. Nevertheless, let me take a moment to mention the food provided last year by Domaine du Mont d’Arbois, which seriously improved the fare during our attempt on the Route de la Découverte. That food—enough to make even the dullest palate salivate—was unfortunately not an option on this trip given our route.

We’ve been sailing on port tack since we left NY, and every night we have been graced by the moon’s appearance. During the night from Sunday to Monday, this precious navigational aid shone with its full force. The ocean has changed from azure blue to a silvery grey, adding to the beauty of the spectacle. We’re enjoying this fully now, as the trades will begin to ease tomorrow. Tomorrow night we’ll start nearing the Doldrums. We’re gently adopting the ideal trajectory to cross this zone, but we all know that it remains unpredictable.

Good night

Nicolas Raynaud

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