Intentional Hydrofoil Ventilation/Altitude Control

I read on the Moth forum of experiments being done to use intentional ventlation of a hydrofoil as a method of altitude control. Has anyone here experimented with this? Any thoughts on the theory?

[tspeer]

There's been a lot of research on the idea of pumping air out onto the upper surface of a hydrofoil to regulate lift. It's attractive to some because it means no moving parts below the waterline. It hasn't been that successful, though. More often than not, the air is simply swept away.

Personally, I think it's a non-starter for a sailing hydrofoil. If it worked, it would cause a lot of drag. Spoilers will regulate lift, too, but they're incompatible with achieving a high lift/drag ratio, which is what sailing hydrofoils are all about.