Wow, lots of opinions here, but nobody touched on what they actually do and how a boat/engine has to be set up properly to take full advantage and not create a dangerous situation.... So, let's dive into 'Hydrofoils 101'.
First thing is that a 'foil generates lift while it's in the water and being moved forward. I think that's pretty obvious and well understood. And the faster it is moved, the greater the lift.
It's the high lift at high speed that causes the AV plate to get broken. It's also this lift that causes the boat to take on a 'bow steer' effect, which can be VERY dangerous at high speed.
So, why the 'foil in the first place if it creates SO many problems? Well, most foils don't carry the right instructions on the packaging, and if they do, it's in really really small print... And what does that print say?
"This hydrofoil is designed to be fitted to engines with a minimum increase in installation height of at least 1" above normal."
Why is that important? Because with the increased height, the foil will come out of the water once the boat is planing! And once out of the water it no longer exerts force on the engine/boat. It's no longer generating lift, putting excess pressure on the AV plate or generating bow steer.
Hydrofoils have there place, but it's not on most boats, unless they are specifically set up for one to be installed. The reason it's not on the packaging is because the sales would be far less! And when has safety ever been considered (by a corporation) higher than that sweet sweet profit?
I hope this clears up hydrofoils for everybody...
Chris.......