French, born in 1990, after graduating from high school in Boulogne-sur-Mer, he crossed the English Channel to Southampton Solent University, where he earned a degree in naval architecture. Today, Sébastien Sainson is director of the Gitana Team Design Office, which produced Gitana 18, the Ultim built by the CDK shipyard in Lorient and launched, also in Lorient, on February 14th. Gitana 18, currently undergoing its first sea trials, is the latest vessel in the “Gitana” saga and the team led by Ariane de Rothschild, CEO of the Edmond de Rothschild Group. Gitana 18 is the result of the joint work of Gitana Team’s in-house design team and Guillaume Verdier’s studio, coordinated by Sébastien Sainson. In this exclusive interview with Top Yacht Design, Sainson discusses his work and how it was born, as well as the features and objectives of the world’s most advanced Ultim.
In Team Gitana for 14 years
How and when did you join Team Gitana? And what was the first boat you oversaw as head of the design office?
I joined in early 2012 to work on the boat building team as a laminator. I was working on the construction of Gitana XV, the Multi70. My first assignment as head of the design office was Gitana 18. On Gitana 17, I had a different role, that of project manager, and I wasn’t yet supervising the entire design office. So Gitana 18 is effectively my first project in this role.
How is the Gitana design team structured, and how many people are there?
The team currently consists of about ten engineers. The design office is made up of eight people, including engineers and naval architects with various specializations, who are regularly joined by one or two interns or trainees. Additionally, there are one or two engineers dedicated to electronics, because, although the tools are constantly evolving, this aspect remains essential. Each team member specializes in their own field: naval architecture, structures, aerodynamics, and mechanical engineering. They also specialize in systems design, sizing, and performance analysis. The team also includes a new generation of engineers focused on software, AI, and development, who are taking on an increasingly important role within the design office.
An interactive work
How does the team coordinate its activities with naval architecture firms and external consultants?
Coordination is based on an interactive working method, founded on a constant exchange of ideas between the Gitana design office and Team Guillaume Verdier. The approach is structured for the long term, while leaving ample room for innovation, without an overly rigid framework that could stifle creativity. In practice, when a new project begins, such as the design of a foil, everyone contributes their ideas, and the work is organized based on these. In naval architecture, the process involves successive design cycles: each component of a vessel generates its own iterations, which ultimately integrate to form a coherent whole. This is where the coordinator’s role comes in: ensuring that the sum of the individual contributions, however rich, forms a coherent overall project and not a simple juxtaposition of individual ideas.
The role of the skipper
Charles Caudrelier. What is his role in technical choices and design decisions?
Charles is a real asset to the team. He is very dedicated to his work and was particularly involved in the design of the Gitana 18, to the point of having sailed very little in the time interval between the two programs, of 17 and 18, such is his passion for the work of the design office. He devotes a lot of time to analysis, asks questions, reviews topics, and always remains open to discussion. This daily interaction is invaluable: like everyone else, he doesn’t necessarily master all the technical aspects, but his perspective as a sailor brings an irreplaceable insight. This is where his essential contribution lies. Together with Erwan Israel (Gitana Team’s performance manager, editor’s note) and the other sailors involved in the project, he ensures that what the engineers envisioned is consistent with reality at sea. When testing options in the simulator, his concrete understanding—how to navigate in the presence of a weather front, how the boat should behave in different conditions—helps the team avoid poor decisions and develop a coherent design for the skipper. Because ultimately, he will be the one sailing alone on the boat that the entire team has designed over the years. He must feel comfortable and able to manage it fully.
A new boat for bold solutions
When did the Gitana 18 project really begin?
The initial idea was born after the 2022 Route du Rhum, won by Charles. It was then that Cyril (Cyril Dardashti, Gitana Team’s financial and administrative director) suggested, rather than limiting ourselves to substantial modifications to Gitana 17, starting from scratch to explore the potential of a new vessel. From December 2022 to June-July 2023, the team worked on this pre-design phase. This phase allowed us to imagine sometimes bold solutions before comparing them to the constraints of reality: available materials, budget, and feasibility. The goal was to present Ariane de Rothschild, our owner, with a concrete vision of what Gitana 18 could be. With the project approved, the actual design phase began in the summer of 2023 and continued well beyond the launch. Some components continued to be developed, designed and built even after the vessel was launched.
The Gitana 17 Experience
Gitana 17 was launched in 2017. Why was it considered obsolete after only a few years, and what were its weaknesses?
Gitana 17 wasn’t obsolete. In fact, it’s now in the hands of another team and remains quite competitive in its Ultim generation. The decision to build a new boat wasn’t born from its flaws, but from an ambition: to achieve performance improvements that subsequent developments no longer allowed for the existing design. Over the years, the team had already developed numerous foil versions—at least four or five actually built versions, not counting the computer-aided ones—and explored nearly every possibility offered by the Gitana 17 platform. New ideas, such as repositioning the boat’s transoms to optimize its appendages, required such extensive modifications that they were no longer feasible, both financially and in terms of time. This turning point led to the decision to start from scratch. The Gitana 17 could have continued to evolve, and still may, but the Gitana 18 represents a much bigger leap in quality.
Gitana 17: a project of its times
What were its flaws?
Truth be told, we really had to look for them! If we really had to identify any, they were more compromises related to the context of the time than actual flaws. When Gitana 17 was designed, foiling was still an unknown: no one had yet succeeded in realizing it. Therefore, we had to design a boat capable of sailing conventionally if foiling didn’t materialize. These compromises sometimes influenced some decisions; for example, the position of the foils. We could have moved them further aft if we’d known from the start that the boat would rely so heavily on the foils. But these aren’t flaws: they were and are simply the consequence of starting from scratch and facing the unknown.
The challenge: integrating complex systems in a tight timeframe
Regarding Gitana 18, what were the main challenges encountered during development?
The most significant challenge was overall coherence and coordination. With a team like Guillaume Verdier’s, driven by a desire to innovate without limits, the real challenge was finding the right balance between ambition and practicality. This delicate balance is the most difficult to maintain. From a technical standpoint, building a platform of this size, with manufacturers like CDK, remains manageable. However, the real challenge today is integrating extremely complex mechanical systems in a very tight timeframe. Two years to design and build such an object is a very short time: in the aerospace or automotive industries, projects comparable to Gitana 18 take decades. Significant time must also be dedicated to the design and optimization of each individual component, otherwise the weight would quickly become excessive.
The use of the autoclave
Did you use new materials in the construction?
Not fundamentally new, but with significant advances in their application. The main difference is the use of an autoclave (about 80% of the Gitana 18’s structure was treated in an autoclave, ed.), which polymerizes the carbon fiber and allows the use of high-modulus, high-performance fibers that were previously not in common use. On this platform, this represents a real advantage. The other key feature of the Gitana 18 is the quantity and complexity of its metal components: Inconel (a family of nickel-chromium superalloys, ed.), titanium, and rare-earth alloys. This isn’t entirely new, but the scale is unprecedented. This raises specific challenges, particularly regarding corrosion, which make the mechanical aspects particularly challenging.
AI: useful, not crucial
Have you used AI in your design?
Initially, very little, but the practice has evolved considerably. For about a year, AI has been used daily in the design office, primarily to more rapidly develop calculation tools, program interfaces, or create data analysis software. These developments would not have been possible so quickly without AI. However, for the actual design of the vessel, AI is not yet the most suitable tool. It is more of a development accelerator than a designer.
30 knots to start
Gitana 18 has completed its first sea trials. What are your first impressions? Generally, very positive. Unlike the Gitana 17 era, when the early days were marked by inadequately sized components, unknown loads, and recurring mechanical problems, Gitana 18 hasn’t encountered any major technical issues since its launch. The complex systems developed over months are working well, the boat’s behavior is as expected, and the rudders and foils respond correctly. That said, the boat hasn’t been pushed to its limits yet: trials are currently limited to speeds up to 30 knots. The real test will come when it begins to fly and accelerate, because that’s when the appendages and structures will be truly put to the test. But already, there’s a simple and tangible satisfaction. After each sea trip, the team can debrief and return home without having to spend the night repairing the boat for the next day’s outing. This, in itself, is a great success.
A team always ahead
What sets Team Gitana apart from other teams?
First and foremost, it’s a culture of innovation and boldness: daring to do things before others. Gitana XV was a first step towards foiling boats back in 2014. Gitana 17, then Gitana 18, confirmed the team’s tradition of taking calculated risks. But this boldness is always part of a coherent framework, with the human and technical resources necessary to achieve it. Having such a well-structured design office is unique in the world of French offshore racing. This allows us to control everything internally, from component design to manufacturing, while maintaining a certain level of confidentiality about the innovations developed and achieving greater responsiveness than a more outsourced approach.
Mine? A unique job!
In your role as head of the design office, what motivates you most? Initially, it was primarily the technical aspect. Seeing such a complex component—a foil, a rudder—arrive and be installed after months of work is incredibly rewarding. Having the opportunity to follow every design phase of such a technologically advanced component, from the first sketch to the finished product, is rare. Few jobs offer such a comprehensive experience, and that’s what makes this job truly unique.
Emilio Martinelli
