M&M’s Gomboc simulator model provides dynamic behaviour predictions and stability insights that inform data-driven design decisions throughout the development process
70–90 per cent lift. Unlike the full foilers seen in the America’s Cup, where yachts fly completely free of the water, we deliberately chose a configuration that retains some hull contact to maximise stability and control. In ideal conditions the PB72 is capable of full foiling but that’s not her mission. Our goal was always to deliver consistent performance across a wide range of wind angles and speeds, especially offshore. One of the challenges with any foiling
configuration is balancing performance in light air. Foils that deliver lift at 18+kts of boatspeed can become a drag liability below 12. To overcome this, we designed the RMFoils to be fully retractable. When retracted, the vertical daggerboards serve as the primary foils, optimised for light-air efficiency and low drag. This retractability gives the PB72 genuine versatility across a range of conditions, ensuring
performance is preserved whether you’re blasting downwind in 20kts or racing in seven knots of wind.
‘100 per cent lift is not only possible but viable on a cruising platform’
A toolbox for innovation Designing a yacht like this requires you to sling out the textbook. The concepts don’t exist in old drawings or handed-down rules of thumb. Instead, we relied on modern simulation tools like Gomboc, a dynamic VPP platform developed by SumToZero and used by Emirates Team New Zealand. With it, we could test and refine every detail – foil shapes, hull shapes, sail configurations – in a dynamic, digital ocean. Gomboc allowed us to take a leap in the
iterative design process. It became our tank and wind tunnel, our racecourse, and our sketchpad. Through thousands of simulations we refined not only how the PB72 sails, but how it behaves in every mode: racing or cruising, reaching
or punching upwind in messy seas. Originally, the call was to shoot for a
50 per cent lift fraction - enough to reduce wetted surface and improve performance without overcomplicating the platform. But thanks to the precision and fidelity of our design toolbox, we quickly discovered that a 100 per cent lift fraction was not only possible, but viable on a cruising- performance catamaran platform. By carefully refining foil geometries through simulation, we unlocked full-foiling potential in a yacht built also for cruising. The results speak for themselves. In
cruising mode, the PB72 sails effortlessly at 12kts upwind and 25kts reaching. In race mode, with the RMFoils deployed and a sharp crew on the handles, she’ll do 26kts upwind and 40-plus downwind. What makes this even more remarkable is that the PB72 doesn’t require an elite team to operate. While offshore racing demands a seasoned crew of eight to nine, she’s fully manageable for a shorthanded team during day sails or
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A CFD/RANS hydroflow visualisation, semi-foiling upwind at 26kts, showing the complex interaction between the hull and appendages
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