Use this table to select sail size for planing


Windsurfing fin-foils have been known for 40 years. FRPGear made it work using modern advancements in composite technology and innovative design. With frontal area (drag) significantly less then Formula fins, the recently developed FRPGear Fly-Fins generate as much lift as Formula boards with less drag to bring any board on fast planing at wind as light as 3 m/sec (for custom options). Because Lift-to-Drag ratio of Fly-Fin is several times better compared to the best boards, it significantly increases combined Lift-to-Drag ratio of the whole system: windsurfer.

This cartoon diagram is simplified. There are more forces involved. But you can have a basic idea why Fly-Fin makes a windsurfer faster. 

Common questions.

How does FRPGear Flex-Foil technology work?

Flex-Foil generates propulsion every time when fin is loaded and when load is released. You can pump the fin to propel forward without wind or you can do nothing and every bump during your ride will generate some propulsion. 

Does the Fly-Fin lift only the back of the board up?

One may mistakenly think that Fly-Fin lifts only the back of the board. This is a misconception. As you can see on our YouTube videos the entire board is up and in planing position. The reason why it seems like the Fly-Fin makes the board look flat is because the board is in fast planing position on low speed. If speed continues to increase, the entire board comes more out of water.

Why is the wing on the very bottom of the Fly-Fin while other known designs have the wing on the middle of the fin?

The deeper the wing—the more efficient it becomes. The wing starts reducing its lift efficiency when the distance to the board is less than the wingspan.

Do I need to reinforce the fin box?

No. For the Fly-Fin you do not need a stronger fin box.

Why Fly-Fin does not have forward offset of the wing like common hydrofoils?

Because it does not need it. Modern boards are small and the offset can be easily compensated by technique. Our 2019 and 2020 models have forward offset for better dynamics.

This simplified force diagram shows why the foil of Fly-Fin has no forward offset.

FIBER REINFORCED PLASTIC (FRP) material is used in advanced process

Structural Integrity

Built with unidirectional S-glass or carbon fibers as the result of our proprietary manufacturing method. Fibers go in the direction of the structural stress all the way from the box to the foil tips.

By placing fibers individually using continuous tow, we achieve the highest mechanical properties. Higher strength allows to reduce cross section, increase aspect ratio, and reduction of the foil thickness resulting in higher hydrodynamic efficiency.

Common situation when fly-fin is used

Other sailors do not see that you are on fly-fin.

This video is taken during a side-by-side run of 5 sq.m. sail on 160-liter slalom board equipped with FRPGear Fly-Fin against 160-liter JP Super Lightwind with OEM fin under 7.5 sq. m. sail.

Now you can sit on it without fin damage:

Custom Fly-Fins for extra light wind planing:

Using larger Fly-Fin delivers much better results versus using a larger sail or wider boards. Use your favorite sail and a smaller board most of the time and change Fly-Fins for different wind conditions.

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