My experience has usually been, a hydrofoil is a last ditch effort to "fix" a poorly set up boat. Poorly running motors, wrong prop, wrong motor height, poor weight distribution in the boat, wrong setback, etc...are your culprits and a hydrofoil just tries to treat the symptom without trying to determine what is causing the disease.
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"Racing ... it's life. Everything that comes before or after is just waiting." -Michael Delaney (Steve McQueen in "LeMans")