Originally, a precursor: Hervé Devaux…


In 1993, Hervé Devaux created HDS and was a forerunner in the introduction of aeronautical computation software to design multihulls. At that point, he participated in the construction of boats for some of the biggest names in sailing. The first of the boats on the list dates back to 1994 and Primagaz, skippered by Laurent Bourgnon. Loïck Peyron’s Fujifilm followed in 1996, then Groupama in 1998…


In 1998, Hervé was joined in his enterprise by Denis Glehen, a young aeronautics engineer specialised in carbon who, on first contact, decided to offer his support, bringing to the table his knowledge at the service of competitive sailing.

Together, they were able to spark off their complementary natures. With an entourage of 2 other colleagues, they forge a legendary track record, playing a key role in the structural design of the top offshore racing yachts. At that point, HDS is surfing the manna of the multihull projects and shore teams, which are becoming increasingly professional and subsequently seek their expertise more and more.

Gsea Design

In 2009, Denis Glehen creates Gsea Design, a new structure, which aims to develop its influence within Lorient’s offshore racing hub, in partnership with HDS.

A highly technological activity:structural design

Playing the go-between in this way to reach a more rewarding balance between the naval architects and boatyards, HDS and Gsea Design apply themselves to the emergence of a new specialism: computers! This high-risk specialism has become an absolute must today in the bid to support the development of major projects in the competitive sailing environment.
Their expertise, enriched by a 20-year old database, has today earned them a position as one of the best in their field internationally.

From the calculator to Ophelia


The special environment in which the studies are carried out prompts the creation of in-house tooling. These include, in chronological order, Depla, Autospar and finally Ophelia. And so it is that ‘Ophelia’ is born, a calculation tool with dynamic simulation capabilities able to reproduce external phenomena with the aim of better understanding the stresses endures by the ‘platform-rig’ assembly. With this in mind, we’re currently in the process of developing a new type of calculation tool integrating the notion of material fatigue and suggesting numerous applications.

Transformation:making Gsea Design’s expertise available across new sectors.

history-eolienneOur general mechanics engineers, who hail from prestigious training centres like Centrale or Polytechnique, have been trained in the merciless school of offshore racing.

From the architects’ sketches, we calculate the slightest parameter using digital simulation software: materials, siting of the mast, gap between the hulls and length, torsion, keels and forms of the famous foil appendages that enable boats to fly above the surface of the water.
Thanks to our in-house ‘Ophelia’ software, fuelled by 20 years of data collection and combined with an advisory approach to the decision-making, our design office boasts truly unique expertise.

Spurred on by the 3rd generation of engineers, like Sébastien Guého, Gsea Design is keen to take on multiform challenges in the calculation of composites: yachting, aeronautics, industry, MRE… whilst remaining very active with regards the core business. Gsea Design is involved with 2 of the 5 teams in the next America’s Cup.

At the same time, Gsea Design’s new human adventure is our house-workshop, which is being built opposite Lorient and will accommodate the entire team. A space designed in which to work and live in an assumed Californian-spirit: latest addition to the blueprint, a surfboard and paddleboard rack.