The foil would get damaged pretty quickly, before actually killing most of the fish it comes into contact with.
The concept is very very old and well known. So there must be practical reasons why this was not commercialized.
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.
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?
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.
Anyway, congrats on the product. It feels awesome.