Foils, from ocean racing to maritime transport

Now tried and tested in the world of ocean racing, foils offer an excellent lever for accelerating the decarbonisation of maritime transport. There are a large number of projects – some of which involve players from Brittany – and some of which have already been implemented. Here’s a closer look.

After a 2020 Vendée Globe that did not allow foil boats to express their full potential, particularly in heavy seas, the 2024 edition has validated their performance and reliability, with the top seven finishers lining up on a latest-generation foiling Imoca (launched between 2021 and 2023), while the first non-foiler, Monnoyeur-Duo For a Job (Benjamin Ferré), took 16th place – Jean Le Cam had finished 4th four years earlier. “These results lend credibility to a technology that has reached maturity, thanks also to the America’s Cup boats and the Ultims,” says a delighted Jérôme Guiban, head of the design office at Pixel sur Mer, a company specialising in flight control for these types of boats. 

This is good news for the Breton industry, which has been working for some years now to put its foiling expertise at the service of more sustainable maritime transport. Like MerConcept, which, after working on the subject of flight in ocean racing (Ultim SVR Lazartigue, Imoca Macif Santé Prévoyance, among others) and launching a prototype of a small electric foiling catamaran, has developed with VPLP Design and Alwena Shipping two passenger catamarans between 24 and 30 metres long, with an average speed of 40 knots and up to 40% lower fuel consumption. The first, the Fast Foiling Ferry, is aimed at transporting the general public, with a capacity of 200 passengers, while the second, the Crew Transport Vessel, is aimed at transferring offshore personnel. 

Both concepts feature major adaptations to suit their transport mission. “Their foils are retractable to limit the draught, facilitate manoeuvring and docking in port, explains Antoine Jarry-Lacombe, project manager at Mer Concept. They are made of steel rather than carbon, to meet the challenges of cost, strength and recyclability of materials.” The designers also have to take account of IMO (International Maritime Organisation) safety standards, which require redundancy of the most critical equipment, including the flight control systems.

Jérôme Guiban confirms: “The safety issue also concerns the ship’s handling. The boat’s balance has to be controlled in all circumstances, including bends and sudden, massive movements of passengers.” In addition to safety, there is also the issue of passenger comfort. “The take-off and landing phases are the most sensitive. Flight control must limit the acceleration and deceleration felt”, continues the head of Pixel sur Mer’s design office. The Lorient-based company has also developed its expertise in competitive sailing, ‘flying’ the Ultims Maxi Edmond de Rothschild and Banque Populaire XI, as well as fitting a flight control system to the TF35 catamarans from Lake Geneva (whose foils were manufactured by another Breton company, Heole Composites). The company has also been able to transfer its experience to the maritime transport sector, working with LMG Marin on a project for a 28-metre electric flying ferry (180 passengers), mainly financed by the Norwegian government – the selection of the shipyard is currently underway. 

A maritime transport sector that still needs convincing

For the time being, however, the shipowners who have enabled these projects to come to fruition are few and far between, and fly foreign flags. The P-12 electric ferry from Sweden’s Candela (30 passengers) was put into service this autumn by the company SL in the Stockholm archipelago. In Ireland, Artemis Technologies should see its 150-passenger EF-24 sailing on Condor Ferries’ Belfast-Bangor route by the end of 2025. With more than a year’s delay. “The economic climate has put the brakes on innovative projects by shipowners,” says Richard Forest, founder of SEAir. A pioneer in this field of flying for individuals, the Lorient-based company has already sold 18 small hydrofoil boats (from 6 to 12 metres), which combine diesel engines, foils with electric pods and a small battery pack. 

With its hybrid boats, SEAir has also won over the defence sector, with the signing of a €10 million contract for 12 and 20 metre launches (for transporting military personnel and drones) designed for rapid action, surveillance and rescue missions, as well as electronic surveillance. They are due to be launched in 2027. All that remains now is to move up a gear and convert the transport companies. “The market is stubbornly striving for zero emissions, with hydrogen propulsion systems that are not yet perfected but are highly subsidised, or 100% electric systems that are expensive and heavy because of the batteries; what’s more, they consume a lot of fuel in rough seas, says Richard Forest. We could save time by starting with diesel engines, which already halve CO2 emissions. They can be changed when hydrogen technology is operational.”

However, K-Challenge, which recently set up in Lorient, has developed a model of hydrofoil chase boat for the Orient Express Racing Team, propelled at more than 50 knots by hydrogen motors, with the foils giving the boat greater autonomy and speed. 

By then, foils will have become even more energy-efficient, continuing to benefit from the developments currently underway for racing yachts, as the technology in this area continues to progress, following the example of the new foils fitted to the F50s on the SailGP circuit since January. Avel Robotics is at the forefront of this field, and is already supplying nine Imoca boats with foils that have a CO2 equivalent 30% lower than conventional models. “They’re made by two robotic arms that work like a 3D printer, so there’s no need for a mould,” explains Adrien Marchandise, co-founder and technical director of the Lorient-based SME. 

The company is going even further with the Foil Infinity project, developed with Compositic and MerConcept and partly financed by the Brittany Region and European funds. Made from recycled carbon and virgin thermoplastic carbon, these foils promise a 30% smaller footprint and a longer lifespan. The technology will be tested in real conditions this year by Adrien Marchandise himself on the Mini 6.50 Minilab Racing Bull, which he will be racing in the La Boulangère Mini Transat, before being adapted for the Imoca boats in the Vendée Globe 2028. Proof that in the field of foiling, ocean racing remains a pioneer.