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.

30.01.2008

A pod of whales.

par Gitana

And 10 minutes later all hell broke loose! Yesterday, Tuesday, during our 13th day at sea, things moved at breakneck speed, as we went from summer to winter, from calm seas to some roughing up. In the early hours of the morning, we were cruising along nicely, all sails set, a lot of canvas flying. We were surprised by the mild temperatures after our first chilly night in awhile. Offshore of the Rio de la Plata estuary, the crew took a saltwater shower in the cockpit. They had no more than 2 liters of fresh water to rinse off, well aware that there wouldn’t be any more for some time. Once clean, we had to hurry back to the gym for one of our favorite workouts: replacing the reaching staysail by the beating one, and dropping the gennaker on the windward side of the solent, which was again unfurled! Time flew by as we stowed the sails and distributed the weight onboard, and the weather changed insidiously, from bright blue to grayish-blue.

Our efforts were rewarded, as we soon saw water spouts all over the place. Look…whales! Grab your binoculars! A few massive backs rose up and then disappeared, reminding us happily—as we crossed our fingers—that we haven’t hit anything since starting out. Humming along nicely, it took less than three days to expertly negotiate our second low-pressure trough. But on this stretch of water running right through the rotating winds, everything changed in just a few miles. A south wind came up from Antarctica, immediately causing the temperature to drop. The azure blue sea turned bottle-green, and the horizon took on a thick cloak of haze caused by the contact between cold air and still-warm water.

In this universe of a thousand shades of gray, reminiscent of a winter cruise down the coast of Brittany, we experienced a moment of pure pleasure with the boat flying softly like a bird. We wouldn’t trade this for anything… And then, in a flash, our brisk gait was shattered by head-on swells that destroyed our momentum. Gitana 13 was no longer gliding…it started banging and bouncing and crashing with all the force of its 25 tons into the waves seeking to impede its progress. Without hesitating, we cut our speed in half, conceding this hopeless battle to the ocean in order to protect the boat. As I type these lines, the seas haven’t settled down. With one reef in the main and the staysail up, plodding along at 17-18 knots, we are continuing our forward march engulfed in a real din, shaken around like never before. Just above me, I hear waves crashing on the three-man watch. Dawn will soon break, and I hope the seas will calm down.

Goodnight

Nicolas Raynaud

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