“L’Hydroptère” has been restored to working order. The 18-metre-long, 24-metre-wide foiling trimaran with a 28-metre mast is once again ready to set sail after years in the shipyard. According to those involved in the project, its return to the water is scheduled for the end of September.
This brings to an end a long period that began in Hawaii in 2019. There, the revolutionary trimaran had been abandoned since 2015 and completely stripped of its equipment. Gabriel Terrasse and Chris Welsh bought it on 28 June 2019 at an auction held by the US state of Hawaii to save it from being scrapped. The Photographic documentation of the L’Hydroptère 2.0 project traces the journey from the abandoned boat in Honolulu to its restoration in Nantes.
Across the Pacific and back to France
Before being transported back to Europe, the boat first had to be refitted so that it could sail under its own power from Hawaii to San Francisco. On 2 November 2019, ‘L’Hydroptère’ set sail under skipper Mike Price. On 18 November, the trimaran reached San Francisco Bay.
After that, dismantling began in preparation for the return journey. The transport to France took place in three stages. The first began in February 2021, and by March 2023 all the parts had finally been assembled in Nantes. It was there that the actual reconstruction began, supported by Eric Rambaud as technical manager, who has experience in aircraft and composite construction.
A foiler from before the current racing classes were introduced
“L’Hydroptère” was designed by Éric Tabarly and Alain Thébault. The idea was radical at the time: hydrofoils were intended to reduce the wetted surface area of the hulls and lift the boat out of the water. Today, foils are a standard feature on America’s Cup yachts, Ultim trimarans, IMOCs and the F50 from SailGP back to the familiar picture. When the concept of ‘L’Hydroptère’ was first conceived, it was still a daring experiment.
The trimaran later became a symbol of this development. “L’Hydroptère” was the first sailing boat to break the 50-knot barrier - a milestone in the history of sailing.
Yet its significance lies not solely in this record. ‘L’Hydroptère’ demonstrates how early on designers sought to combine aerodynamic and hydrodynamic principles in sailing. The reconstruction of this legendary trimaran is therefore also the restoration of a technological artefact of its time.
“L’Hydroptère Nouvel Horizon” will soon be setting sail
The planned launch at the end of September is not yet proof that ‘L’Hydroptère Nouvel Horizon’ – as the trimaran is now called – will be able to fly again straight away. After years out of service, a journey in pieces and a complete rebuild, the structure, systems and dynamic behaviour on the water must first be tested.
That is precisely the difference between a restoration that looks good and a foiler that is operational again. The planned test runs are intended first and foremost to check the technical platform; only then can we consider whether the trimaran will take to the water again.
In the long term, Lorient is earmarked as a further location. There, ‘L’Hydroptère Nouvel Horizon’ could be on display at events, exhibitions and sailing competitions.
Book recommendations
Winning regattas on dinghies and yachts provides a clear overview of the technical aspects of competitive sailing. Fred Imhoff covers equipment, forces acting on lines and fittings, sail trim, and the influence of wind and current. The book thus complements the history of ‘L’Hydroptère’ by explaining the principles behind the measures regatta boats use to increase their speed and maximise their potential on the water.
Tune up to win focuses on the relationship between boat set-up and speed. The book explains how the rig and appendages generate speed, how sail profiles can be adjusted to wind strength and course, and the role played by boat preparation. For readers, it makes the challenging task of fine-tuning a foil trimaran accessible – even though the technology involved goes far beyond standard regatta practice.
Looking back, how would you assess the concept behind ‘L’Hydroptère’: a bold milestone in foil development, or too uncompromising from a technical perspective to ensure long-term success?
Martin Hager
Editor in Chief YACHT