Culmination of a revolutionary design

The idea of a cruising catamaran is appealing. Lots of space. Supremely stable. Minimal draft allows for epic anchorages. But the sailing is a hassle. If you’ve bareboated, you’ve likely seen charter cats under power.

Perhaps that’s why the MODX 70 is turning heads, recently awarded the title of Multihull of the Year 2025m at the International Multihull Show in La Grande-Motte. This catamaran has wings that offer 35% extra power over conventional sails, and when you push a button, they disappear.

Here’s a report from VPLP, designers of the MODX 70:

The MODX 70 is equipped with two inflatable, automated and retractable wingsails and electric propulsion, in accordance with the demanding and visionary design brief put together by French shipyard Océan Développement whose CEO is none other than Franck David, instigator of the MOD70 class back in 2008.

The modernity of the MODX 70 can be distilled into this brief definition: a large vessel with ultra-simplified handling and unlimited range that doesn’t use fossil fuels.

“Wingsails have been part of the discourse for a while now, but everyone has been waiting for a real flagbearer for the technology. It’s fantastic to see MODX pursue this ambition. This boat is neither a prototype nor a demonstrator. She’s just the first series catamaran yacht to be entirely self-sufficient in all aspects of her propulsion,” says Mathias Maurios, head of VPLP’s Cruising Division.

While the hull construction was entrusted to the Neel yard in La Rochelle, the systems and interiors were fitted by the Océan Développement yard run by Franck David, former Olympic windsurfing champion at Barcelona 1992. As for the wingsails, they were developed by a new company: Aeroforce.

At VPLP, the architectural design “began with structural and aerodynamic studies, two intimately linked subjects on this catamaran,” says Stéphane Dérobert, recruited in 2021 by VPLP’s agency in Nantes to manage this project.

The idea of placing a single wingsail at the center of the vessel was quickly eliminated, the platform between the hulls being structurally insufficient. “The twin wingsail solution was the inevitable choice,” says Dérobert. “The studies showed that adding a flap to the trailing edge would allow the rig to achieve the same performance as a single wingsail on most points of sailing. But we still had to put the theory into practice!”

This is where Aeroforce, offshoot and technological partner of the MODX project – and patent holder of the innovation – comes in. The MODX 70’s wingsails are currently the first to be both inflatable and retractable, set on a telescopic mast, and with fully automated trimming for incidence and camber. Both wingsails have been installed and the boat is currently undergoing sea trials at Lorient before sailing to La Grande Motte.

The lateral implantation of these wingsails was also given much thought. “We had to maximize the length of the booms while making sure they wouldn’t touch when goosewinged for downwind sailing,” says Dérobert.

Lastly, the coachroof has been extended considerably towards the outboard side of the hulls, leaving a minimal sidedeck for harbor maneuvers. Under sail, crew and passengers move from one cockpit to the other via the inside.

“Stepping the wingsails in the hulls frees up the center of the boat entirely, multiplying the possibilities considerably,” says Maurios. The crew can circulate around the helm station at the center of the vessel, which gives the steerer a view of more than 270 °, and access the doors leading to the bows.

Much of the superstructure is glazed and its wide design was extensively studied to integrate the systems, in particular the wingsail booms, but also the 75 square meters of solar panels that contribute to the vessel’s electrical self-sufficiency. Under sail, the bulk of the battery charging is provided by two 40 kW electric motors connected to propshafts that are left to spin freely in hydrogenerator mode.

“This was another reason why we needed to design a relatively light boat with a high length to beam ratio. This elongated form guarantees high performance, and high performance guarantees electrical self-sufficiency. This is the key to the virtuous circle Franck David wanted to achieve right from the very start of our discussions,” explains Dérobert.

Visionary and pioneering, the MODX 70 features many other innovations, such as the tender well in the rostrum, the use of natural textiles for the interior upholstery, and the 40% biosourced resin in the PET cored layup of the hulls.

The first build of the series, which is already being commercialized, has been presented at the International Multihull Show where she was awarded Multiyacht of the Year prize at the 2025 Multihull of the Year Awards. This is a very good start for this catamaran carrying 10 to 12 passengers on eco-friendly charters in marine protected areas.