Matt,
Let me play editor here for a minute so there is no confusion about what you said, because I am not clear on it.

In your first paragraph you said, "any lifting device, no matter how efficient, definitely falls withing the realm of what should be considered a hydrofoil."

Did you mean "no matter how inefficient"?

And in paragraph 2 you said, "...what is clearly restricted in the F18 regulations..."

Were you referring to the F16 regulations?