[SAILING] Extreme load cases: cruising expertise

GSea Design is developing its expertise in the cruising sector. A logical transfer of skills from racing boats to pleasure craft? Not really. Though the two categories share similarities in images, the comparison ends once it comes down to structural calculations. Maeg, an engineer, spent eight years working for a pleasure craft certification body, before bringing her expertise into play at the service of GSea Design.

On the water, two parallel worlds combine but the links between offshore race boats and cruisers tend to be in short supply. The former, largely prototypes, make wide use of carbon and are starting to fly, whilst constantly striving for improved performance, even if it means totally sacrificing comfort. The latter, production boats, are built of glass sandwich and now favour all that offshore racing delivers on: extreme stability, ‘better than home’ equipment and increasingly wide openings in all the bulkheads to offer a greater sense of space and visibility.
“We’re working on all types of cruising platforms, monohulls and most notably catamarans. The specifications favour ergonomics and the structure is designed to be adapted. They’re evolving towards more openings with portholes everywhere and glazed windows. These boats are kitted out with fully equipped kitchens and bathrooms and the load cases studied are extreme. We’re essentially working on the “distortion”, which is significant on multihulls. When the hulls work, the glazed windows should continue to close properly! The stiffness of the structure is vital.

GSea Design complies with all the regulations published by certification bodies like ICNN or Bureau Véritas, with which the engineers from Lorient regularly collaborate to refine these texts.

At the same time as the ‘classic’ monohulls and multihulls, a new category of so-called ‘cruising’ boats has been created. GSea Design has notably got involved in the studies into fast foiling boats like the “Foiler” built by the ENATA yard, as well as the famous Seabubbles!


Every year, the Yacht Racing Forum is the place to be to decipher the future of offshore racing, both in terms of economic and technological development. On this last point, GSea Design is a key interlocutor and two of its engineers have been invited to express themselves. For the first time, GSea Design plays at home, in the Sailing Valley ... Lorient.

 “Appendages and foils in particular are no longer the future of offshore racing. They are the present.” Maël, the first to take the floor, sets the scene. “The future will be about making gains in terms of performance and hence understanding. It’ll be important to develop and analyse embedded data and then we’ll be able to design boats able to remain stable on their own

GSea Design is already working on data collected via sensors that cover the whole foil. The Recala software, which has been developed by the team in Lorient, is capable of making a three-dimensional analysis of the foil’s distortion and measuring the stress it has undergone in terms of load. Soon, this data could be accessible as a live stream by the crews themselves, whilst sailing.

Maël will also speak about Sofia, the software developed by GSea Design to optimise the appendages. “This software is linked to an important research on foils and the aim is to optimize the appendage in order to obtain the final sought-after distortion.”

 Higher, faster…

Joseph will be speaking about a more general-interest topic which, despite well knowned in the Sailing Valley, is a lot less common on the international scene: the development of the Ultims Class. How far will they go? “In geographical terms, these multihulls are already going very far as they are circumnavigating the globe. We don’t know their limits yet in sailing terms. Today, our focus is on safety. Safer boats are a prerequisite for any new gains in performance. Servo control enabling better management of the foil will lead to boats going higher, faster”, Joseph assures us.

[The Yacht Racing Forum, which will be held in Lorient for the first time (following Denmark, Malta and Geneva), is a major gathering for competitive sailing protagonists. As such, each year discussions are split into two main areas debated by the world’s top specialists: business and marketing on the one hand; design and technology on the other.
At the Palais des Congrès and the Cité de la Voile, in Lorient, on 22 and 23 October.]

[Data] The challenges of digital transformation: KIRIKO, the Quick Rig Computation

This year, between digital transformation and GDPR, technology forms an integral part of GSea Design’s daily life. Digital tools, historically designed for the company’s core activity, are becoming a central factor in communication with our clients. Following a few months of development, KIRIKO is the first tool we’re unveiling today.

KIRIKO, which stands for QUIck RIg COmputation, is a proportioning tool, which enables us to respond as promptly as possible to your requests for a mast weight estimate.

This application is available online here >>

Upon acceptance of your registration request, you’ll have access to the following interface:

This web page, will enable you to select the features of your request: mast type (spreader, wing, diamond…), boat type, construction details and the various data necessary for processing the request.

The data at your disposal will be as follows:

  • Estimated mass of the tube with reinforcement
  • Cable features (Class EA and load)
  • Conceivable mould geometry