Departure of the engine from the water

Friends, who can explain to a novice why the hydrophilic does not fly out of the water by a motor? Is this achieved by the skill of the rider? Insufficient engine thrust? Or self-stabilization of a hydrofoil? Or for some other reason?

Is there such a problem at all?

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I’m not sure what you mean specifically but the guy in the picture jumped above/through a wave, he’s an experienced e-foiler, probably a company presenter, so he has to show off.
Why the wing stays in the water and doesn’t “fly” out? It’s a matter of positioning yourself correctly (it’s a skill too) on the board/leaning forward just enough to keep the front wing flat in the water, you also need to practice the right throttle position that’s pretty much how you control the amount of lift you get from your wing.

In this photo, the athlete is doing this on purpose. And I’m interested in the modes in which this can happen involuntarily. And how not to enter these regimes.

When I was studying, the engine often came out of the water. With experience, you will learn to avoid this.

Just don’t have to much Weight at the back of the board, how he is doing this is very quickly shifting all of his weight to the back of the board and the foil will pop out of the water if you’re doing jumps with efoil or any foil board you’ll need straps to hold your feet to the board.
Have you efoiled or been on a regular foil board?

I’m design and building my Efoil board. And now I’m trying to understand the theory of flights on it. I am interested in hydrofoil hydrodynamics. And its modes of operation. Including the exit of the motor from the water.

I want to understand the theory. I do not want to copy what is already there thoughtlessly. If I understand the essence of existing wing designs and their advantages, then I will take them into account in my design.

Hello, I’m not sure that I understand your question but I will try to help:

Do you want the foil / mast / motor to jump clear of the water? Or do you want to avoid this?

In the image the rider is intentionally jumping the wing out of the water, the motor is not contributing to this jump (except providing speed).

To jump the foil and motor out of the water, all that is required is sufficient speed and placing pressure on the back foot, this is very easy for even an inexperienced rider.

Landing successfully is another story…

I am trying to interpret your comments, do you want to create a system that would avoid this condition?

If so this would require significant automation of either the motor (thrust vectoring) or active control of the rear stabilizer. I would recommend not attempting either of these things :grinning:

Do you have much foil riding experience? I see in the comments you say you are a novice, with practise you can control the angle of attack to prevent the foil from breaching the water surface with balance, there is no need for any automation on the motor or foil to control this.

Thanks for the answer! I wanted to avoid this effect. But now I realized that it was all about the skill of the rider. I want to build a efoil and collect information. Some points are not very clear to me. So I’m trying to figure out the theory. And I ask stupid questions.

Wing (like airplane wing) gives certain amount of lift with speed. Depending on shape/thickness, its more or less stable/maneovurable. No lift outside of water. With “passive” foil wing, its all about rider skill. Help comes from some kind of mechanism which helps to control some or all 3 axis, computer based or human reaction based. Rest is pure hydrodynamics.