Sailing the new foiling Birdyfish dinghy – Yachting World | Gmx Pharm

The BirdyFish is a tender that aims to make foiling accessible to sailors of all skill levels. François Tregouet took it for a test sail to see if it really puts foiling within reach

Based on a final project from an engineering school, three young French people have created the BirdyFish, a dinghy that aims to make foiling accessible to everyone.

BirdyFish is the story of a sailing start-up, something western France does well. Near Nantes, Jean-Baptiste Morin, Pierre Rhimbault and Alban Satgé were not yet 25 years old when they began to create a new class of boats. They were fascinated by foiling designs, from the small yachts Mini Transat to the IMOCA 60s, but wanted to make flying on the water easier.

Ambitious but realistic, the trio focused on the business and management of the project, turning to specialists for key areas. Naval architect Etienne Bertrand, known for his work on the Mini, was commissioned to design the BirdyFish, with a wide bow reminiscent of the 6.5m Mini ocean cruisers.

With their personal savings and a 10,000 euro grant from a foundation for young entrepreneurs, they built a prototype. Three years later, they are close to completing a €250,000 fundraiser and moving to a 600m2 building to scale up mass production.

While the fuselages are subcontracted a few miles south, the wings are built in-house in Nantes, a key factor in quality control of these essential parts.

Under the gennaker, the flight experience begins in less than 10 knots of wind. The crew position determines the trim. Photo: BirdyFish

The foil design was entrusted to a master of art, Jean Baptiste Behm. With their J-shape, the foils generate maximum lift when fully deployed, yet remain fairly easy to retract. The carbon sheets weigh 10kg each and are symmetrical so they can be used on either side of the boat. This simplifies production and after-sales service.

Also for the sake of simplicity, the position of the foils is fixed, without adjustment. Rudder tilt can be adjusted, but to allow good rudder control, the rudder profile is not extreme.

A longer rudder chord means a little more resistance, but also more tolerance and less risk of losing control. Sailing at low speeds with a smaller rudder area would give no feel to the tiller, making it much more difficult for beginners. It took more than two years to develop the Birdyfish and to refine this balance.

unsinkable

The hull is made of a glass-polyester sandwich, weighs 93 kg and has four watertight zones making it unsinkable. The mast is aluminum and once the foot is released it can be dropped backwards with a crew member controlling the descent with a halyard in hand.

The top speed recorded by a BirdyFish is 22 knots (like a class 40 but 40 times cheaper!). Photo: MULTImedia/François Tregouet

The BirdyFish is limited to three sails to keep it simple. There is no trapeze either, the righting moment is entrusted to the foils. This is also a safety decision as any fall at high speed can be dangerous. Two crew members sit on the gunwale or move slightly outwards against the wind with their feet in the straps.

A major advancement in the development of the BirdyFish also means there is no longer a sword. The first boats sold played their role as pioneers, but it turns out that the foils, despite being symmetrical, create more anti-drift effect than expected. Removing the dagger board and its box made the Birdyfish’s cockpit even simpler.

Each foil weighs only 10 kg (22 lb) and they are symmetrical port and starboard. Photo: MULTImedia – François Tregouet

Officially, the BirdyFish will fly in from 12 knots of wind. But with a trained crew, the boat can take off from as little as 8 knots. Finding the right angle, generating just the right amount of force at the right time to lift the hull out of the water will tell the difference between a novice crew and one that already has a few hours of flying experience.

Rusted from decades of cruising on non-foiling boats (and having long since forgotten my 420s and minis), trying out the BirdyFish felt like a good test of its true accessibility for all. I returned to shore reassured about my abilities – but more importantly, overwhelmed by the extraordinary sensations of flying.

Off La Rochelle beach, the BirdyFish flew very quickly at about 15 knots in a wind that varied between 10 and 15 knots. High speed means constant vigilance is essential: the transparent Mylar window in the boom helps with visibility.

There are no more lines at the foot of the mast than on a classic dinghy: simple. Fittings are placed in such a way that watertight zones are not compromised. Photo: MULTImedia – François Tregouet

Since there are no flaps to adjust the boat’s trim, the crew’s position must be adjusted. Sitting on the windward side of the boat, well wedged against the shroud, I was quietly enjoying the boat’s stability – its forgiving foils and T-shaped rudders doing a remarkable job – as Jean-Baptiste Morin handed over the helm.

I was instructed to use as little head angle as possible instead of using the mainsheet first as an accelerator and then as a damper. The miracle happened very quickly and we took off! Soon we were flying, perfectly dry just above the chop.

G force

I quickly learned that you have to react very sensitively to movements in order to keep foiling. Rudder correction angles must be as small as possible. Moving the entire tiller is out of the question, instead Jean-Baptiste advised keeping my hand on the tiller close to my body and making only small movements with just the span of my fingers.

During transport or storage, the self-leveling J-Foils fit into the cockpit. Photo: MULTImedia – François Tregouet

Course deviations must also be very limited. I estimate that the maximum allowable is more or less 2° around the true wind direction without trimming the sails. The penalty for overdoing it is immediate: the BirdyFish will land either gently or more violently.

Tacking and jibing aren’t difficult, but doing them in flight mode requires a bit more experience. To demonstrate this, Jean-Baptiste took control of the boat for a series of foiling jibes. Crouching forward in the cockpit my role was limited to manipulating and more importantly holding onto the Solent sheet as the rate of tack is brutal, a reminder of the exceptional performance achieved.

The foil case is slightly smaller than its slot. The foil rake setting is fixed by four screws: no mental work required. Photo: MULTImedia – François Tregouet

Only twice have I reached 18 knots on my first attempt at the helm of a sailboat and that was on a Gunboat 68 and an 80ft Ultimate trimaran – very different budgets than the standard £15,000 BirdyFish.

Three key options bring the bill up to €21,200 – it’s hard to do without the jib furler for manoeuvring, a Code 0 with furler offers lightweight air performance, and a launch trailer is essential for the 135kg (297lb) total package – but if you want to go foiling on a manageable budget and with little experience the BirdyFish rocket hits the target.

BirdyFish Specifications

LOA: 4.70 m / 15 ft 5 in
Beam: 1.90 m / 6 ft 3 in
Draft: 0.90 m / 2 ft 11 in
Shift: 135kg / 297lb
Sail area against the wind: 13.5m² / 140ft²
Downwind sail area: 24.5m² / 258ft²


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