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.

25.01.2008

Struggle with the elements.

par Gitana

Generally, sailing in the trade winds is a beautiful thing. Here, colors are uncommonly intense—one look at Gitana 13’s blue hull gleaming in the sun and gliding over the deep blue sea elicits pure rapture.

Also, thanks to the mild weather, we don’t have to change out of our t-shirts and shorts even if they repeatedly get wet from the spray. And then there are those exceptional moments, like when the wind comes to life for no apparent reason. This happened on Thursday, just before the sun reached its zenith. From a solid 20 knots, the wind rose to 22, 23, 24 knots. We were flying the solent, with one reef in the main. This simple acceleration transformed the boat from a state of gravity to one of weightlessness. Such a wondrous impression of lightness, of seemingly unstoppable power, is born when the speedometer rises above 25 knots.

It’s felt by everyone onboard immediately. We became more attentive to the sail trim—and to the helmsman’s face—in a mix of smiles and concentration. With the wind coming from 90°, the experience is intoxicating, as the windward hull skims the waves on the way to rising high in the air. Thanks to its weight-to-power-to-width ratio, Gitana 13 is able to take off on a single bound. Playing the sheets and the tiller to stay up on one hull is an exercise in pure yet forbidden pleasure if we want to make it to San Francisco. Therein lies the difference between a one-day joyride and a long-distance race like ours. You have to treat the equipment differently.

The solent is wisely replaced by the staysail, but not for long. This wind gust dissipated almost as quickly as it formed. After that we flew the solent and full mainsail in trade winds of only 12-16 knots—not strong enough for our taste. The result: 480 miles over the past 24 hours, with the hope of doing at least as much today. But we’ll have to go a little faster. In front of us, along a latitude just north of Rio de Janeiro, a storm front is building right in our path. We’re now in a race against the clock. Regardless of who wins—us or the clock—the amount of time gained or lost will be significant. Record attempts are a constant struggle with the elements. And we love it.

Good night

Nicolas Raynaud

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