Fin innovation: Is TRUDIFIN closing the gap between fin surfing and foiling?

"In order to increase efficiency in the light wind range without giving up the classic feel of a fin, I have developed a new, modular fin system with the TRUDIFIN. developed", writes inventor Rudolf Schwerma. It is a fin with a lift-producing horizontal wing that can be replaced. This allows the board's trim to be individually adjusted to body weight, surfing conditions and riding style. The technology is protected by a granted Austrian patent. The design is available in complete data sets and is optimised for injection moulding tools and CNC machining. Multi-year test series with G10 and hybrid carbon variants have been running since 2024.

Modular design for customised trim

"My aim was to utilise the physical advantages of the additional lift and still retain the familiar fin feel. Thanks to the modular design, every surfer can now fine-tune their board to their own body weight, surfing conditions and personal riding style for the first time," explains Rudolf Schwerma. The system combines a classic fin with a horizontal wing element. The wing geometry can be varied using interchangeable modules, allowing the lift to be adapted to different requirements. The design aims to maximise efficiency in the lower wind range without losing control as the wind increases.

Technical implementation and compatibility

The fins are available in lengths between 28 and 40 centimetres, while the blade sizes vary between 150 and 500 square centimetres depending on the model. The materials used are hybrid CFRP-GFRP or G10 high-pressure laminate. Production takes place as a press laminate from a CNC mould, the surface is finely roughened and hydrodynamically optimised. The system fits all commercially available windsurf boards and is compatible with standard fin boxes such as Powerbox, Tuttlebox and Deeptuttlebox.

Target groups and market positioning

According to the developer, the system is aimed at three main groups: Beginners and intermediates who want to get planing faster, as well as freeriders who want to efficiently trim their setup for light winds. In the B2B sector, TRUDIFIN is targeting surf schools as well as board and fin manufacturers as potential licence holders. The concept envisages co-branding solutions: Established brands can expand their portfolio via the "Powered by TRUDIFIN" label. The vision is to make windsurfing easier and more individualised. The TRUDIFIN is intended to bridge the gap between the desire for early planing and the necessary control when the wind picks up.