Since its inception, the development of the pleasure yachting industry has always been incremental, based on trial and error and aesthetics. In the few cases where research was undertaken, the primary tool was the towing tank. Small-scale models were towed in large pools, measuring their resistance. A complex, time-consuming, and uncertain process was then required to derive the full-scale boat’s resistance. Ultimately, if the towing tank was used, it was more for final analysis than for design optimization.

Today, things have changed significantly, but return on investment is still the key metric for every shipyard. Therefore, a cautious approach to innovation remains. By how much must one improve hull performance (speed, fuel consumption, comfort, etc.) to justify the cost of the R&D required to achieve it? And will the end customer be able to appreciate this improvement? In contrast, in the related field of yacht racing, such as the America’s Cup, R&D resources are said to be «unlimited,» and the only ROI is whether or not a trophy is won.

Some shipyards have realized that working with these racing teams is the best way to make the «technology transfer» necessary to make a leap into the commercial world.

The Bluegame shipyard, part of the Italian San Lorenzo Group (one of the largest in the world), has long been betting on an alliance with Caponnetto-Hueber SL (a leader in racing design with thirty years of experience in the America’s Cup). Together, they designed the 50-knot hydrogen-powered foiling catamaran required by the rules for every racing team in the 37th America’s Cup, as a support boat for the races.

The success of this boat convinced the shipyard to translate some of its acquired knowledge into a commercial product, the BGF45, adapting the extreme potential of the racing prototype to a cost-effective compromise, but always in the spirit of innovation and market differentiation. Finding this compromise, a relative optimum, can sometimes be more complex than the search for the absolute optimum, such as maximum speed at all costs.

Here the objective is to find the best compromise between cost, visual impact, comfort, fuel consumption and seaworthiness, among others, a target that therefore requires a balance between variables from different categories

SIMCENTER, and the CFD code START-CCM+, are the key tools used at Caponnetto-Hueber SL to approach this problem.  After dozens of tests on different configurations, a so-called «foil-assisted» configuration was chosen, where the foil (the submerged wing that lifts the boat) is designed so that the rear of the hull remains in the water. This makes it possible to have foils that do not require a complex and expensive dynamic lift control system, a compromise between cost, complexity, and fuel economy. While a fully foiling boat like the HSV can reduce drag by 80% compared to a conventional boat, a foil-assisted one can reduce it by 30-40%.

This is still a huge achievement for an industry where improvements are typically single-digit. But the use of SIMCENTER went far beyond the topological choice of foils. Seaworthiness is key for a boat to face the ocean, and this involves a combination of structural calculations, fluid-structure interaction (FSI), seakeeping analysis, stability and maneuvering.

On the BGF45, the lack of a foil control system and movable surfaces that can adapt to changing sailing conditions means everything must work harmoniously as designed, with no possibility of modifications at sea. The choice of simplicity for the end customer offloads complexity to the designer. This is where the power of a digital twin comes into play.

Simulation and visualization of calculation results, turning trajectories, and wave impact, as well as, for example, the ability to see in color the details of the foil vortices interacting with the hull, are the «link language» that allows communication between experts and shipyards. At the same time, shipyards are embracing a more scientific language and vision of design, which ultimately benefits the end buyer.

This is, according to Mario Caponnetto, who has lived and promoted this evolution over the last four decades, the greatest result that could have been expected.

The BGF45 has attracted considerable interest at recent boat shows, not only for its environmental sustainability due to its reduced fuel consumption, but also for its comfort features, the result of tons of CFD calculations. It’s reasonable to hope that other shipyards will follow this path and this design approach, leading to increasingly technologically advanced and high-performance boats.

But the innovation Siemens contributed to the success of the BGF45 goes beyond what has been said. It also involves the adoption of semiconductor-based SENTRON ECPD (Electronic Circuit Protection Device) technology.