XR41 - a World Champion is born
Having been part of the creation of the new XR41 for X-Yachts, it is a great relief to see the boat perform on the water and fully deliver on expectations by winning the World Championship in the ORC B class. And not only winning—claiming 1st, 2nd, and 4th place in the final standings—is a clear statement of what we have achieved with this design.
In the summer of 2023 I received a call from Thomas Mielec. Thomas wanted to know if I would be interested in designing a new ORC weapon for X-Yachts. The design would be a collaboration between X-Yachts, Max Gurgel from Vmax Yachting, and myself, representing C Performance.
In late 2023 we had our kick-off meeting, where Max and I presented our approach to tackling this ambitious project. Time was tight, so we decided on a semi-parametric approach: we would test different families of hulls, then develop new families based on our findings—hoping to slowly (or quickly!) converge on an optimal hull shape.
Max, being a machine learning wizard with a master degree in physics, gradually built a framework capable of handling our high demands—generating large numbers of hulls, producing ORC rating numbers, and ranking them in a very short timeframe.
As a naval architect and CFD engineer, my role was to take the best-performing hulls and test them in a specially developed CFD setup. This allowed us to simulate only a limited number of points while still producing a highly reliable VPP for each hull.
The results from the ORC VPP and our CFD-based VPP were then combined and ranked before being presented to X-Yachts. On their end, we worked closely with Thomas and Tobias Merkel, who were keeping all the strings together—because while we were developing the hull, the rest of the boat's design and engineering was progressing in parallel.
Approximately four months after starting, we delivered the final hull design. In yacht design, that's an incredibly short timeframe. But we were proud—we had created something fresh, something we hadn't seen before, and something that would turn heads. And the performance numbers from the VPP were simply mind-blowing.
Next up was finalizing the keel and rudder design. We have a special approach here: where most designers rely on known profiles—often scaling them to fit new appendages—we treat each design individually. We use AI and genetic algorithms to generate custom profiles, meaning no two boats share the same keel or rudder profile, as every operating point is slightly different. We can generate around 10,000 profiles per hour to find the best fit for a specific boat.
On top of the AI-generated profiles, we dedicate significant time and energy to designing the bulb and verifying rudder position using CFD. We knew that the position of the rudder was crucial and the beamy hull would lift the centerline and the rudder out of the water, so getting the position right was crucial. When we look at the boat today going upwind, I think this was very well achieved—there is hardly any wake seen coming off the rudder, as it is perfectly placed in the wake system of the keel and the control of the boat is always fully intact.
Finalizing the design of the appendages gave some relief after months of hard work, but also a sense of stress and anxiety, knowing that we had delivered and that there was nothing we could do about it as everything was in production now.
A little over a year after we started the project, the first hulls came off the production line, bringing great relief. The XR41 looked stunning as she was floating in front of the X-Yachts facility in Haderslev. Sitting in the water exactly as we had initially designed her to, she was a bit of a glamour girl. And soon to become a cover girl of various sailing magazines, when she started shaking up the race track around the Baltic Sea.
The XR41's debut on the race track was the culmination of our work. The boat performed exactly as intended—sweeping the leaderboard and securing first place overall. We had done what we could; now it was up to Jesper Radich and his crew to take her through her paces. The team delivered and has, so far, won everything they have touched: Maior, Round Funen, Round Sealand, Kiel Week, German Championship, and now the Worlds in Tallinn.
Obviously, many people have been involved in this project, but I want to give a special shout-out to those I've had the pleasure of speaking with and working alongside. Thank you—it's been a true pleasure.
Anders Bastiansen
Bouwe Bekking
Chris Williams
Hannes Renzsch
Heine F. J. Sørensen
Jesper Feldt
Jesper Radich
Kræn B. Nielsen
Max Gurgel
Michael Richelsen
Thomas Mielec
Tobias Merkel
Javier Jaudenes