Most yachts that promise to run on nothing but wind and sun turn out to be renderings. The MODX 70 is not. Its first hull has already logged roughly 6,000 nautical miles, took Multihull of the Year 2025, and did it all with two inflatable wings where the mainsail used to be.
That is the part worth slowing down for. Not an electric drivetrain bolted onto a normal sailing catamaran, but a rig rethought so the boat can feed itself. The idea its builders keep coming back to is "energy sobriety" — sizing the sail power so precisely that the yacht needs no fuel and no generator to cross an ocean.
Wings you can deflate
The two masts carry AF125 inflatable wings, 125 m² each, developed by Aeroforce. The skin is TPU, pumped up to roughly 100 mbar in about eight minutes, stretched over a 23 m telescopic rotating mast built in six sections. When the wind gets serious, a deep reef trims the sailplan down to 65% of its area; a trailing flap swings out to add another 30 to 40% of lift when you want it.
Rigid wing sails are not new — they have won the America's Cup — but they are fragile, expensive, and impossible to stow. You cannot reef a solid wing, and you certainly cannot drop it at anchor in a blow. An inflatable wing sidesteps all of that. Deflate it, telescope the mast down, and the whole thing stows.
The builders claim the wing is about 1.7 times more efficient than a conventional rig of the same area, worth something like a 35% gain in power. Whether the number holds in every condition matters less than the shape of the bet: more drive from less sail, handled by one person pushing a button.
That last point is the one that actually changes things. An experimental rig is only useful if a short-handed crew can run it. On the MODX 70 the wings are one-button, single-hander operable, which is what turns a science project into a boat you can take to sea.
A hull that runs on its own weather
Under the deck sits a 250 kWh LFP battery bank, feeding two electric motors turning variable-pitch props. Those props do double duty: at speed they spin the other way and regenerate, pulling roughly 16 kWh back into the bank at 15 knots of boat speed. Under power alone the range is modest — about 110 nautical miles at 5 knots — but that misses the point. The motors are there for harbors and calms, not for crossings.
The crossings run on sunlight and passing water. Around 70 m² of solar panels peak at 15 kWp and bring in 30 to 50 kWh on a good day. Two 400 L rainwater tanks and enough stored energy give the boat roughly ten days of habitability fully off-grid. The hull itself leans green: a layup that is 40% biosourced resin over a PET core.
The sums are meant to close on their own. Sun and regenerated water refill the bank; the wings do the moving; nothing on board asks for diesel.
Who built it, and how fast it goes
The MODX 70 comes out of Océan Développement in La Rochelle, with the hull built by the Neel yard and the naval architecture by VPLP Design — Marc Van Peteghem and Vincent Lauriot-Prévost, the office behind a long line of record multihulls. The wing technology is Aeroforce's.
The performance is not shy. The first hull has recorded 21.5 knots in a 25-knot breeze, and the design brief was blunter than any top-speed figure: 10 knots of boat speed in 10 knots of true wind. Jean Guyon, who runs Aeroforce and serves as MODX's chief commercial officer, frames the whole project around that ratio.
Jean Guyon, Aeroforce CEO / MODX CCO:“The MODX's goal was to be energy independent — in 10 knots of wind, we should do 10 knots of boat speed.
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VPLP's Mathias Maurios puts the ambition in category terms, calling it "the first series catamaran yacht to be entirely self-sufficient in all aspects." The word that matters there is "series." Océan Développement plans two to four boats a year, which turns a one-off proof into something you could actually order.
Why it matters
Plenty of yachts have gone electric. Fewer have asked the harder question: if the boat has to make its own energy, how much sail does it really need, and how do you make that sail small enough to handle yet powerful enough to matter? The MODX 70 answers by pairing an inflatable wing with a retractable mast — the first production yacht to do so — and then sizing everything else around it.
The MODX 70 is not a concept boat. It is the first production catamaran to run entirely on wind, sun, and regenerated water — with inflatable wings a single sailor can raise at the push of a button, proven over roughly 6,000 nautical miles at sea.
The price stays undisclosed, which tells you who it is for right now. But the engineering underneath is the interesting part, and it is already floating. For anyone who has watched "self-sufficient" mean "renders and a press release," a boat that has sailed 6,000 miles on its own weather is a different kind of claim.
Photo: Océan Développement / Ronan Gladu.
