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Comment by Candelaboat | Hacker News Reader

Weeds can be an issue, unless the foils just cut through them. Taking off in a weed heavy water can be tricky, just like operating a jetski, a jet boat or a regular prop boat. It is true that a fish wouldn't fare too well either when hitting the leading edge of the foil, which is submerged to about 0.7 meters.

However, the foil can take quite a beating.

Regarding commercialization, which is a great question in itself, our experience tells us that it's due to: 1. It's hard to build controllable foils, especially in a "miniaturized" size like a 8 meter boat. 2. the technology to enable sufficient speed of electronic foil control hasn't been cheap nor good enough prior to the advent of consumer drones & smartphones.

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As an electrical engineer, I'm intrigued. Do you actually control the angle of the foils during travel?

Is it to maintain a set height or change height too. I know that too high, and the boat becomes unstable.

I know that retracting the foils is a simple thing, relatively speaking.

However, if you are actually controlling the foil angle, isn't the technology available for decades? I mean there are cooling water pumps that change the impeller vane angles during operation at 400 - 700 RPM, there are helicopter blades that change angles, ship propellers can also change angle during operation, etc. There are many examples.

What technical problem have you specifically overcome in this case?

Great question. What's different in our case is that the flight controller captures the boat’s movements from 7 sensors. Then it establishes the full-state 3×6 state matrix (position, velocity and acceleration with regards to position in x, y and x and rotation around the same axis). This is partly done using sensor fusion algorithms.

We then use the outputs to control the angle of attack, along the longitudinal axis of the foil, essentially twisting it. The R&D that has gone into making this work reliably enough for a consumer product is our secret sauce.

I have a lot of questions and doubts, but I guess this would not be the best place to ask them.

Anyway, congrats on the product. It feels awesome.

Helicopter blades change angles mechanically as controlled by human input. I presume the big ship propellers are the same, except they're probably more "set-and-forget"? Obviously the automatically-adjusted foils of a speedboat this size are a completely different situation.

Is anyone working on applying electronic foil control to sailing? I'm asking this under the assumption that foil sailing is universally human piloted because it's meant to be a challenging sport and I might be wrong in that. But if it's human piloted I could easily see room for a hybrid approach where propulsion is provided by wind but controls are powered and automated to make it more approachable.

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