The twix-efoil project

Let’s see where this will lead us … everybody’s comment welcome.

Following @noahark very nice 3D drawing about a crazy ironing board based foil idea:upside_down_face:


Where to install the pod ?
Front wing: needs to be tested but you could mess up the water flow for the stab
Rear wing: best position for a single drive IMHO

We could position a third wing at the junction of the masts (eg 500cm2) plus a small and fast front wing (700cm2) so that you have an extra surface for a early take off. Once the take-off has occured, the third wing goes out of the water and you accelerate because you loose suddenly 1/2 of the drag… Let’s call it the 2x-efoil or twix efoil, an x-shaped mast with 2 lifting surfaces :upside_down_face:

Not sure this would work as a kitefoil (because the fuselage acts as a anti-drift surface when the kite pulls downwind), but since we have a propulsion pushing forward, this diserves to be tested !

Perfect project for dual direct drive…


For a flush x-junction, I suggest a simple halved joinery… this should be ok during a hard fall as the stress is spread over 2 mast heads …

However, the X-setup could bypass the stab counter torque (Fwing = pos lift, stab = neg lift) and create balance issues, that’s why a tandem or canard setup with 2 surfaces of positive lift might be more appropriate:

  • front wing with positive lift (400cm2)
  • rear stab with positive lift (250cm2)
  • central wing with positive lift (650cm2)


  • rear wing with positive lift (400cm2)
  • front wing with positive lift (250cm2)
  • central wing with positive lift (650cm2)

With canard or tandem setup, we could give up the crossed-mast setup and mount a straight mast over each wing but we would loose the central wing allowing very early take-off.
How to fix a mast that is 45 degrees to the board bottom ?

@soefoil if you want me to add anything or modify the drawing, I am happy to.

I was thinking all one piece for the 2X dual mast configuration, but that defeats the purpose of your original design? You were thinking one of the main benefits was portability?

Let me know what to add to it…

Thanks @noahark. Portability was the original goal. I think there are a few ideas to validate from the rigid X (dual drive, 3rd wing, canard or tandem drive).
Everyone is welcome to comment or propose ideas.