This is explained on wikipedia: https://en.wikipedia.org/wiki/Hydrofoil#Foil_configurations https://en.wikipedia.org/wiki/Hydrofoil#Foil_configurations Basical

This is explained on wikipedia: https://en.wikipedia.org/wiki/Hydrofoil#Foil_configurations https://en.wikipedia.org/wiki/Hydrofoil#Foil_configurations Basically, yes, for fully submerged hydrofoils you need to make sure you don't get too high or low. For surface-piercing you don't, they self-stabilize.